Paper coated with synthetic alkali metal alumino-silicates

ABSTRACT

A family of synthetic alkali metal aluminosilicates (SAMS) are produced by the hydrothermal reaction between kaolin clay and alkali metal silicates. The integrated composition of the SAMS products is a unique entity having an overall composition of 
     
         xM.sub.2 O:Al.sub.2 O.sub.3 :ySiO.sub.2.zH.sub.2 O 
    
     where x is the number of moles of alkali metal oxide and is an integer from 0.01 to 2.0, M is an alkali metal, y is the number of moles of SiO 2  in the unique SAMS compsoition, and z is the number of moles of bound water and is an integer ranging from 1.0 to 5.0. The composition essentially comprises altered kaolin clay platelets with an integral rim or protuberance of essentially amorphous alkali metal silicate-kaolin reaction product. The unique SAMS compositions are structured materials in which the structure can be controlled, and are therefore useful as functional fillers, as TiO 2  extenders, as silica extenders or as reinforcing agents for paper, paint, rubber, plastics and specialty products.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a division of application Ser. No. 07/116,805, 11/3/87, now U.S.Pat. No. 4,812,299, which is a continuation-in-part of Ser. No.06/875,120, 6/17/86.

FIELD OF THE INVENTION

This invention relates to novel and unique synthetic alkali metalalumino-silicate (SAMS) compositions and, more particularly, tosynthetic alkali metal alumino-silicates produced by the hydrothermalreaction of kaolin clays and alkali metal silicates. The preferredmethod entails the hydrothermal treatment of an aqueous dispersion of aclay pigment with an alkali metal silicate at molar ratios of alkalimetal silicate base (B) to clay (C) of less than 1.0, but SAMScompositions and mixtures of SAMS and zeolites can be formed at B/Cratios greater than 1.0. The SAMS compositions have specific advantagesas reinforcing extenders or functional pigments for paper, paints,rubber and polymer systems among its many uses. The SAMS compositionsare particularly useful in paper filling compositions and in papercoating compositions.

BACKGROUND OF THE INVENTION

Alkali metal silicate materials, such as sodium alumino-silicates, arewell known. Broadly speaking, there are two kinds of alkali metalalumino silicate materials known in the prior art--the natural and thesynthetic alkali metal alumino-silicates.

The alkali metal alumino-silicates known as natural zeolites are minedproducts which are crystalline in nature. Synthetic alkali metalalumino-silicate products are either amorphous or crystalline reactionproducts. The crystalline synthetic alkali metal alumino-silicates arealso called synthetic zeolites. Various types of amorphous syntheticalkali metal alumino-silicates are known as well as synthetic silicasand alumino-silicates.

In order to fully appreciate the present invention it is necessary todraw the appropriate distinctions between the unique compositions of thepresent invention and the prior art compositions of specific silicas andsynthetic silicates referred to in general above.

Zeolites

The prior art description of the nature of zeolites can be found in theU.S. Pat. No. 3,702,886 and is incorporated herein by reference.

Both natural and synthetic zeolites can be broadly classified ascrystalline alkali/alkaline earth metal alumino-silicates having uniqueproperties. Synthetic zeolites are ordered, porous crystallinealumino-silicates having a definite crystalline structure within whichthere are a large number of small cavities which are interconnected by anumber of still smaller channels. The cavities and channels areprecisely uniform in size. Since the dimensions of these pores are suchas to accept for adsorption molecules of certain dimensions whilerejecting those of larger dimensions, these materials have come to beknown as "molecular sieves" and are utilized in a variety of ways totake advantage of these properties.

Such molecular sieves include a wide variety of positive ion-containingcrystalline alumino-silicates, both natural and synthetic. Thesealumino-silicates can be described as a rigid three dimensional networkof SiO₄ and AlO₄ in which the tetrahedra are cross-linked by the sharingof oxygen atoms whereby the ratio of the total aluminum and siliconatoms to oxygen is 1:2. The electrovalence of the tetrahedra-containingaluminum is balanced by the inclusion in the crystal of a cation, forexample, an alkali metal or an alkaline earth metal cation. This can beexpressed by formula wherein the ratio of Al to the number of thevarious cations, such as Ca/2, Sr/2, Na, K, or Li, is equal to unity.One type of cation can be exchanged either in entirety or partially byanother type of cation utilizing ion exchange techniques in aconventional manner. By means of such cation exchange, it has beenpossible to vary the size of the pores in the given alumino-silicate bysuitable selection of the particular cation. The spaces between thetetrahedra are occupied by molecules of water prior to dehydration.

Prior art techniques have resulted in the formation of a great varietyof synthetic crystalline alumino-silicates. These alumino-silicates havecome to be designated by letter or other convenient symbol, asillustrated by zeolite A (U.S. Pat. No. 2,882,243); zeolite X (U.S. Pat.No. 2,882,244); zeolite Y (U.S. Pat. No. 3,130,007); zeolite K-G (U.S.Pat. No. 3,054,655); zeolite ZK-5 (U.S. Pat. No. 3,247,195); zeoliteBeta (U.S. Pat. No. 3,308,069); and zeolite ZK-4 (U.S. Pat. No.3,314,752), merely to name a few.

Zeolite Identification

Zeolites A and X may be distinguished from other zeolites and silicateson the basis of their x-ray powder diffraction patterns and certainphysical characteristics. The composition and density are among thecharacteristics which have been found to be important in identifyingthese zeolites.

The basic formula for all crystalline sodium zeolites may be representedas follows:

    Na.sub.2 O:Al.sub.2 O.sub.3 :xSiO.sub.2 :yH.sub.2 O

In general, a particular crystalline zeolite will have values for x andy that fall in a definite range. The value x for a particular zeolitewill vary somewhat since the aluminum atoms and the silicon atoms occupyessentially equivalent positions in the lattice. Minor variations in therelative numbers of these atoms does not significantly alter the crystalstructure or physical properties of the zeolite. For zeolite A, anaverage value for x is about 1.85 with the x value falling within therange 1.85±0.5. For zeolite X, the x value falls within the range2.5±0.5.

The value of y is not necessarily an invariant for all samples ofzeolites. This is true because various exchangeable ions are ofdifferent size, and, since there is no major change in the crystallattice dimensions upon ion exchange, the space available in the poresof the zeolite to accommodate water molecules varies.

The average value for y determined for zeolite A is 5.1. For zeolite Xit is 6.2.

In zeolites synthesized according to the preferred prior art procedure,the ratio of sodium oxide to alumina should equal one. But if all theexcess sodium present in the mother liquor is not washed out of theprecipitated product, analysis may show a ratio greater than one, and ifthe washing is carried too far, some sodium may be ion exchanged byhydrogen, and the ratio will drop below one. It has been found that dueto the ease with which hydrogen exchange takes place, the ratio ofzeolite A lies in the range of ##EQU1## The ratio of zeolite X lies inthe range of ##EQU2## Thus the formula for zeolite A may be written asfollows:

    1.0±0.2Na.sub.2 O:Al.sub.2 O.sub.3 :1.85±0.5SiO.sub.2 :yH.sub.2 O

Thus the formula for zeolite X may be written as follows:

    0.9±0.2Na.sub.2 O:Al.sub.2 O.sub.3 :2.5±0.5SiO.sub.2 :yH.sub.2 O

y may be any value up to 6 for zeolite A and any value up to 8 forzeolite X.

The pores of zeolites normally contain water. The above formulasrepresent the chemical analysis of zeolites A and X. When othermaterials as well as water are in the pores, chemical analysis will showa lower value of y and the presence of other adsorbates. The presence inthe crystal lattice of materials volatile at temperatures below about600 degrees Celsius does not significantly alter the usefulness of thezeolite as an adsorbent since the pores are usually freed of suchmaterials during activation.

Prior Art Patents

Synthetic alkali metal silicates, such as sodium alumino-silicates, aregenerally produced by the reaction of alum with alkali metal silicates.The resulting product usually has a silica to alumina molar ratio ofabout 11. Amorphous products of this type are known. For example,amorphous products of this type are sold by the J. M. Huber Corporationunder the trademark ZEOLEX®. Specific examples of these products, aswell as methods of their preparation are disclosed in U.S. Pat. Nos.2,739,073; 2,848,346 and 3,582,379.

None of these patents teach or even suggest the synthesis of the uniquecompositions of the present invention by the hydrothermal reactionbetween alkali metal silicate bases and clay at preferred molar ratiosof silicate base to clay of less than 1.0.

Synthetic silicas are also known which are produced by the reaction ofsodium silicates and sulfuric acid at temperatures of about 80 degreesC. The products usually have fixed molar ratios. Various products ofthis type are known in U.S. Pat. of Satish K. Wason under Nos.3,893,840; 4,067,746; 4,122,160 and 4,422,880. Products of this type aresold by J. M. Huber Corporation under the ZEO®, ZEOSYL®, ZEOFREE® andZEODENT® trademarks.

None of the above mentioned patents teach or even suggest the synthesisof the unique compositions of the present invention by the hydrothermalreaction between alkali metal silicate base (B) and clay (C) atpreferred molar ratios of B/C or silicate base to clay of less than 1.0.A comparison of the Fourier Transform Infrared (FT-IR) spectra of anamorphous synthetic silicate (ZEOLEX 23), an amorphous silica (Hi-Sil233) and a synthetic alkali metal alumino-silicate (SAMS) of the instantinvention is shown in FIG. 1.

Various zeolite products are also known which are produced syntheticallyby the reaction of sodium aluminate and sodium silicates at temperaturesof less than 100 degrees C. This reaction, in general, proceeds to forman intermediate gel or amorphous material which then crystallizes.Zeolites of this type are sold commercially under the designations,zeolite A, zeolite X, zeolite Y, as well as others. These zeolites finduse as absorbents, ion exchange agents, in catalysis and in other areas.A detailed discussion of this art is provided in U.S. Pat. Nos.4,443,422 and 4,416,805 and is hereby incorporated herein by reference.

None of these patents teach or remotely suggest the synthesis of theunique compositions of the present invention by the hydrothermalreaction between alkali metal silicate base (B) and clay (C) atpreferred molar ratios in the batch reaction of B/C or silicate base toclay, of less than 1.0. A comparison of the infrared spectra (FT-IR) ofzeolites A, X, and Y with a synthetic alkali metal alumino-silicate(SAMS) prepared by the method described in the instant invention isshown in FIG. 2.

The reaction of sodium silicate with kaolin clays has been studied undervarious hydrothermal conditions, as reported by Kurbus, et al, Z. Anorg.Allg. Chem., 1977, Volume 429, pages 156-161. These reactions werestudied under hydrothermal conditions using essentially equivalent molarratios of the kaolin and sodium silicate with the reaction being carriedout in an autoclave. The products of the reactions, as identified byx-ray, electron microscope, and infrared methods, showed that sodiumsilicate reacts with kaolin to form an alumino-silica gel or acrystallized zeolite mineral analcime of the formula:

    Na.sub.2 O:Al.sub.2 O.sub.3 :4SiO.sub.2 :2H.sub.2 O.

In the reaction, the kaolin dissolves and alpha-quartz simultaneouslyappears in the product of reaction.

Kurbus reference specifically teaches the synthesis of a prior artcrystalline zeolite mineral called analcime. This reference does noteven remotely suggest the synthesis of the unique compositions of thepresent invention.

For simplicity, the unique compositions of the instant invention aredescribed as x-ray amorphous materials having attenuated kaolin peaks.The materials will be described in greater detail under the summary ofthe invention. An FT-IR comparison of analcime with a SAMS compositionof the present invention is also given in FIG. 2.

Various reactions of kaolin clays with basic reagents have been studied,including reactions with sodium hydroxide, calcium hydroxide, and thelike.

U.S. Pat. Nos. 3,765,825 and 3,769,383 to Hurst, for example, studiedthe high temperature, high pressure reaction of slurries of clay withalkali metal hydroxides, such as sodium hydroxides. In this reaction,the kaolinite was decomposed and transformed into alumino-silicamaterials. None of these patents even remotely suggest about thesynthesis of the unique composition of the present invention by thehydrothermal reaction between an alkali metal silicate and kaolin clayat preferred molar ratios of silicate to clay of less than 1.0.

Various synthetic amorphous sodium alumino-silicate materials have beenproduced, as described in U.S. Pat. No. 4,213,874, by the reaction ofsodium silicate and sodium aluminate. This patent does not teach or evensuggest the synthesis of the unique composition of the present inventionby the hydrothermal reaction between an alkali metal silicate and kaolinclay.

In U.S. Pat. No. 3,264,130, a hydroxide of barium or calcium is reactedwith a siliceous material. This patent does not teach about thehydrothermal reaction between an alkali metal silicate and kaolin clay.

An amorphous precipitated sodium alumino-silicate pigment is produced inU.S. Pat. No. 3,834,921 by the reaction of sodium silicate and aluminumsulfate. The example of Pat. No. 3,834,921 teaches about the synthesisof an alumino-silicate pigment of the silica to alumina ratio of about11.5. The product is produced by reaction of aluminum sulfate and sodiumsilicate.

None of the above mentioned patents teach or remotely suggest about thesynthesis of the unique compositions of the present invention by thehydrothermal reaction between alkali metal silicate base (B) and clay(C) at preferred molar ratios of silicate base to clay, or B/C, of lessthan 1.0.

In U.S. Pat. No. 4,075,280, zeolite A is produced by the reaction of acalcined clay with sodium hydroxide. This patent teaches about a newprocess for the preparation of well known prior art zeolite A of welldefined x-ray pattern.

Rod-shaped microcrystalline particulates are produced in U.S. Pat. No.3,837,877 by the reaction of the kaolin clay and an alkali metalhydroxide at molar ratios of hydroxide to clay of at least 2:1. Thispatent does not even remotely suggest about the synthesis of uniquecompositions of the instant invention from the hydrothermal reactionbetween an alkali metal silicate and kaolin clay.

In U.S. Pat. No. 3,784,392, a method is described for preparing finelydivided alumino-silicate pigments from kaolin clays by the hydrothermaltreatment of kaolin clay dispersions with an alkaline earth metalhydroxide, usually calcium hydroxide. The reaction is carried out usinga molar ratio of the hydroxide to the kaolin pigment of at least 1:1 attemperatures of 50 to 200 degrees C under hydrothermal conditions. Theproduct produced is an amorphous alumino-silicate pigment havingincreased brightness and having particular utility in coating paper.This patent does not even remotely suggest a reaction between an alkalimetal silicate and kaolin to produce unique compositions of the presentinvention.

None of the prior art patents teach the synthesis of novel alkali metalalumino-silicate compositions described herein. The products of thepresent invention are unique and their preparation under the disclosedreaction conditions is truly unexpected. For the sake of brevity, thesynthetic alkali metal alumino-silicates of the instant invention arereferred to as SAMS throughout the body of this patent.

A further background concept necessary to fully appreciate the presentinvention is that of "structure." As used herein, in relation to alkalimetal alumino-silicates, the structure concept is as follows:

It is possible to synthesize alkali metal alumino-silicate or SAMSproducts with varying structure levels in analogy to the structuredefinition set forth in U.S. Pat. No. 3,893,840 to S. K. Wason of J. M.Huber Corporation. Since no universally accepted industrial method forparticle size determination of synthetic fillers exists and since it iscommon practice of filler suppliers to perform the rub-out oilabsorption test, ASTM-D.281, on their products, the definition ofstructure is arbitrarily based on the oil absorption values rather thanthe filler particle size. Conforming to the same definition as in usefor silica structure, e.g., S. K. Wason, "Cosmetic Properties andStructure of Fine Particle Synthetic Precipitated Silica," J. Soc.Cosmet. Chem. 29, 497-521 August 1978), the synthetic alkali metalalumino-silicates or SAMS products are called VHS (very high structure)type when the oil absorption values are above 200 ml/100 g and VLS (verylow structure) type when the oil absorption values are below 75 ml/100g. The classification of the synthetic alkali metal alumino-silicate orSAMS compositions based on "structure" is shown in Table I as it relatesto oil absorption.

                  TABLE I                                                         ______________________________________                                        DEFINITION: SAMS STRUCTURE                                                    VERSUS OIL ABSORPTION                                                                            Oil absorption                                             Structure Level    (ml/100 g)                                                 ______________________________________                                        VHS     (Very High Structure)                                                                        Above 200                                              HS      (High Structure)                                                                             175-200                                                MS      (Medium Structure)                                                                           125-175                                                LS      (Low Structure)                                                                              75-125                                                 VLS     (Very Low Structure)                                                                         Less than 75                                           ______________________________________                                    

The present invention provides novel synthetic alkali metalalumino-silicate or SAMS compositions and methods for their preparationwhich are unique and unexpected in view of the knowledge of the priorart involving the reaction of clays and alkali metal silicates.

SUMMARY OF THE INVENTION

The present invention relates to a novel family of unique syntheticcompositions hereinafter designated as synthetic alkali metalalumino-silicates or "SAMS" or simply SAMS. The products of the instantinvention relate to a novel family of unique synthetic materials whichare shown by transmission electron microscopy (TEM), FourierTransform-Infrared spectroscopy (FT-IR), x-ray diffraction (XRD), andelectron diffraction (ED) to be unique in composition and morphology andwhich characteristically contain as a minor portion partially alteredkaolin particles which give the characteristic peaks for kaolin seen inthe x-ray diffraction patterns of the SAMS compositions, but which alsocontain as the major portion a non-diffracting amorphous ormicrocrystalline reaction product primarily around the edges, but alsoto some extend over the face of the altered kaolin particle asillustrated by TEM FIGS. 18 through 23.

The TEM FIGS. 18 to 23 show the SAMS product to be altered kaolinplatelets having an integrated rimmed area of amorphous, non-diffractingalkali metal silicate-kaolin reaction product. The integratedcomposition of the SAMS product is a unique entity having an overallcomposition of:

    xM.sub.2 O:Al.sub.2 O.sub.3 :ySiO.sub.2 :zH.sub.2 O

where x is the number of moles of alkali metal oxide and M is the alkalimetal, y is the number of moles of SiO₂ in the SAMS composition, and zis the number of moles of bound water.

The unique products are further characterized by X-ray diffraction (XRD)as being essentially amorphous and having attenuated kaolin peaks asillustrated by FIGS. 33, 34, 35 and 36. The SAMS products are alsocharacterized as having infrared spectra (IR) which differ from the IRspectra of the starting clays, zeolites, and both crystalline andamorphous silicas and silicates. FIG. 1 compares the infrared spectrumof a SAMS composition with the spectra of an amorphous syntheticsilicate (Zeolex 23) and silica (Hi-Sil 233), and with calcined kaolinclay. FIG. 2, likewise, compares the infrared spectrum of a SAMScomposition with the spectra of zeolites A, X, Y, and analcime. In bothFIGS. 1 and 2 the infrared spectrum of the SAMS composition isconsiderably different than the spectra of the other materials. In FIGS.3 and 4, the infrared spectra of the SAMS compositions of Example Oneand Two are compared with their respective starting clays. In bothcases, the spectra of the SAMS compositions are considerably differentfrom the spectra of the starting clays, even though the area in the800-400 wavenumber region is quite similar for both clay and SAMS. Themajor spectral different is the 1200-875 wavenumber region where theSAMS compositions exhibit a broader, less detailed Si-O stretching peak(1200-950 cm⁻¹).

For simplicity, the SAMS compositions will be described as beingessentially multicomponent materials comprising altered kaolin clayplatelets integrated with one or more adjacent areas of essentiallyamorphous alkali metal silicate-kaolin clay reaction product.

The preferred unique compositions of the present invention are preparedby the hydrothermal reaction of an alkali metal silicate and clay makingsure that the B/C ratio of the batch compositions are less than 1.0, butby no means limited to values less than 1.0, where B represents themoles of alkali metal silicate and C represents the mol of kaolin clayin a batch composition. While the preferred SAMS compositions areproduced at B/C ratios of less than 1.0, unique SAMS products can alsobe produced at a B/C ratio substantially greater than 1.0 by adjustingthe batch composition, pressure, temperature, and reaction time of thehydrothermal reaction. This unique batch composition is heated in astirred reactor using a steam pressure of 50 psi to 360 psi andpreferably between 90 to 150 psi for a reaction time of 15 minutes tofour hours and more preferably between 45 minutes to two hours. At theend of the desired reaction period, the reactor is cooled and the uniqueSAMS product is filtered, washed, dried and milled to the desired degreeof fineness. The alkali metal silicate referred to as base in the SAMSreaction has a SiO₂ to alkali metal oxide ratio of 1-6. When the alkalimetal silicate is sodium silicate, the SiO₂ :Na₂ O ratio is preferably2.0-3.3, and a preferred sodium form of SAMS composition is producedwhich can be expressed in terms of mole ratio of the oxides as follows:

    xNa.sub.2 O:Al.sub.2 O.sub.3 :ySiO.sub.2 :zH.sub.2 O

where x is an integer with a value from 0.01 to 2.0, y is an integerwith a value greater than 2.0, and z is an integer from 0 to 10 andpreferably 0 to 5.0. Correspondingly, when the alkali metal silicate ispotassium silicate, the preferred SiO₂ :K₂ O ratio is 2.8-3.9, and whenthe alkali metal silicate is lithium silicate, the preferred SiO₂ :Li₂ Oratio is 4.8-5.6.

It is, accordingly, one object of the present invention to provide novelsynthetic alkali metal alumino-silicate (SAMS) products or pigmentswhich are useful as reinforcing agents, reinforcing extenders,functional fillers, and/or opacifiers for paper, paints, plastics, andother specialty products.

A further object of the invention is to provide a method for theproduction of novel synthetic alkali metal alumino-silicate products bythe reaction of clays and alkali metal silicates under hydrothermalconditions using unique batch composition and controlled reaction time,temperature and pressure conditions.

It is a general object of the present invention to produce value addedunique compositions from relatively inexpensive kaolin or relatedmaterials, which products are controlled structure synthetic alkalimetal alumino-silicate products made from mined and refined kaolin.

Yet another object of the invention is to produce unique kaolin basedcompositions of higher brightness and significantly higher opacity thanthe starting kaolin products.

Another objective of the instant invention is to provide unique SAMScompositions of very low abrasion properties when compared with calcinedclays, and to provide synthetic pigments of superior paper coatingproperties over calcined clays. Another object of the instant inventionis to provide unique synthetic products which can extend expensivefunctional fillers, extenders, pigments and value added products such ascalcined clays, fumed silicas and silica gels, synthetic silicates,synthetic calcium silicates and related compounds.

Yet another important and particular object of the invention is toprovide unique SAMS compositions of high scattering coefficient andexcellent opacifying properties for use in extending the expensivetitanium dioxide compositions in such end-use applications as paper,paints, rubber and plastic concentrates.

A still further object of the invention is to provide articles ofmanufacture comprising paper, latex paints, plastics, paint flatting,rubber, dry liquid carrier, defoamers, antiblocking, and other productscontaining, as a reinforcing agent or functional filler or extender, anovel synthetic alkali metal alumino-silicate product produced by thehydrothermal reaction of clays and alkali metal silicates.

Other objects and advantages of the present invention will becomeapparent as the description thereof proceeds.

In satisfaction of the foregoing objects and advantages, there isprovided by this invention synthetic alkali metal alumino-silicates(SAMS) which comprise altered kaolin clay platelets integrated with oneor more adjacent areas of essentially amorphous alkali metal silicatebase-kaolin clay reaction product, and which are of the general formulaxM₂ O:Al₂ O₃ :ySiO₂ :zH₂ O, wherein x is the number of moles of alkalimetal oxide, M is the alkali metal, y is the number of moles of SiO₂,and z is the number of moles of bound water. These products may becharacterized as substantially amorphous with attenuated kaolin peaks ascharacterized by the present state of the art x-ray diffraction, and yetmay be considered micro-crystalline at a future date as the learningcurve in the characterization of SAMS type products increases. Thepresent invention provides unique SAMS products which are shown by TEMto be amorphous compositions integrated with altered kaolin platelets.The SAMS products have oil absorption values ranging from 40 to above200 ml/100 g, surface areas ranging from 2 to 300 m² /g, high monovalentcation exchange capacities of the order of up to 200 milliequivalent/100g and very low abrasion characteristics.

Also provided by the present invention is a method for production ofthese synthetic alkali metal alumino-silicate products which comprisesthe hydrothermal reaction of a slurry of a clay with an alkali metalsilicate wherein the preferred molar ratio of alkali metal silicate base(B) to clay (C) in the starting reaction mixture is less than 1.0,although unique SAMS compositions can be produced at ratios higher than1.0 under preselected reaction conditions.

There is also provided by the present invention compositions comprisingpaper, paints, plastics, rubber, defoamer, and specialty products, whichcontain the novel synthetic alkali metal alumino-silicate materials ofthis invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to facilitate the understanding of this invention, referencewill now be made to the appended drawings. The drawings should not beconstrued as limiting the invention but are exemplary only.

FIG. 1 Shows a comparison of the FT-IR scans of Zeolex 23, an amorphoussodium alumino-silicate, Hi-Sil 233, an amorphous synthetic silica,Hycal, a calcined kaolin, and the SAMS composition from Example Two.

FIG. 2 Shows a comparison of the FT-IR scans of zeolites A, X, Y andanalcime with that of the SAMS composition from Example Two.

FIG. 3 Shows a comparison of the FT-IR scans of the SAMS compositionfrom Example One with the starting Omnifil clay.

FIG. 4 Shows a comparison of the FT-IR scans of the SAMS compositionfrom Example Two with the starting Hydragloss 90 clay.

FIG. 5 Shows the comparison of the FT-IR scans of Hydragloss 90 and SAMScompositions prepared at B/C ratios of 0.5 (Example Two), 1.0 and 2.0(Example Five, Tests No. 1 and 2, respectively).

FIG. 6 Shows a comparison of the FT-IR scans of the SAMS compositions ofExample Six prepared from Omnifil clay and different mole ratio sodiumsilicate bases using a B/C ratio of 0.5.

FIG. 7 Shows the comparison of the FT-IR scans of the SAMS compositionsof Example Nine prepared from Hydragloss 90 and 2.5 mole ratio sodiumsilicate at B/C ratios of 0.75 to 5.0.

FIG. 8 Shows the comparison of the FT-IR scans of the SAMS compositionsof Example Nine prepared by the reaction of Hydragloss 90 and sodiumhydroxide at B/C ratios of 0.75 to 5.0.

FIG. 9 Shows the scanning electron microscope (SEM) photograph ofZeolite A.

FIG. 10 Shows the SEM photograph of zeolite X.

FIG. 11 Shows the SEM photograph of zeolite Y.

FIG. 12 Shows the SEM photograph of analcime.

FIG. 13 Shows the SEM photograph of the SAMS composition of Example One.

FIG. 14 Shows the SEM photograph of the SAMS composition of Example Two.

FIG. 15 Shows the TEM photograph of prior art amorphous sodiumalumino-silicate, Zeolex 23.

FIG. 16 Shows the TEM photograph of prior art amorphous syntheticsilica, Hi-Sil 233.

FIG. 17 Shows the TEM photograph of prior art calcined clay, Hycal

FIG. 18 Shows the TEM photograph of the SAMS composition of the presentinvention derived from Omnifil east Georgia clay at a B/C ratio of 0.75(Example One).

FIG. 19 Shows the TEM photograph of SAMS composition of Example One.

FIG. 20 Shows the TEM photograph of the SAMS composition of the presentinvention derived from Hydragloss 90 east Georgia clay at a B/C ratio of0.5 (Example Two).

FIG. 21 Shows the TEM photograph of the SAMS composition of Example Two.

FIG. 22 Shows the TEM photograph of the SAMS composition of the presentinvention derived from Hydragloss 90 at a B/C ratio of 1.0 (ExampleFive, Test No. 1).

FIG. 23 Shows the TEM photograph of the SAMS composition of the presentinvention derived from Hydragloss 90 at a B/C ratio of 2.0 (ExampleFive, Test No. 2).

FIG. 24 Shows the TEM photograph of the control Omnifil clay.

FIG. 25 Shows the TEM photograph of the control Hydragloss 90 clay.

FIG. 26 Is the XRD scan of zeolite A.

FIG. 27 Is the XRD scan of zeolite X.

FIG. 28 Is the XRD scan of zeolite Y.

FIG. 29 Is the XRD scan of analcime.

FIG. 30 Is the XRD scan of Zeolex 23.

FIG. 31 Is the XRD scan of Hi-Sil 233.

FIG. 32 Is the XRD scan of Hycal.

FIG. 33 Is the XRD scan of the SAMS composition of Example One showingonly attenuated kaolin peaks.

FIG. 34 Is the XRD scan of the SAMS composition of Example Two showingonly attenuated kaolin peaks.

FIG. 35 Is the XRD scan of the SAMS composition of Example Five, Test 1showing only attenuated kaolin peaks.

FIG. 36 Is the XRD scan of the SAMS composition of Example Five, Test 2showing only attenuated kaolin peaks.

FIG. 37 Is the XRD scan of the starting Omnifil clay.

FIG. 38 Is the XRD scan of the starting Hydragloss 90 clay.

FIGS. 39A and 39B show the SEM photograph of potassium SAMS compositionsof Example Four. Test 2 (FIG. 39A) and Test 4 (FIG. 39B).

FIG. 40 shows the SEM photograph of platey SAMS composition derived fromHydraprint clay at a B/C ratio of 0.25 (Example Eleven).

FIG. 41 shows the SEM photograph of platey SAMS composition derived fromHydraprint clay at a B/C ratio of 0.75 (Example Thirteen).

FIG. 42 shows the SEM photograph of Hydraprint clay used in thepreparation of platey SAMS composition derived from Hydraprint clay at aB/C ratio of 0.75 (Example Thirteen).

FIG. 43 shows the TEM photograph of lithium SAMS composition derivedfrom Lithsil 4 lithium silicate and Hydragloss 90 at a B/C ratio of 0.75(Example Fourteen, Test No. 3).

DESCRIPTION OF PREFERRED EMBODIMENTS

The synthetic alkali metal alumino-silicates (SAMS) of the presentinvention are unique products which are eminently useful as reinforcingagents or functional fillers for paper, paints, plastics, rubber andspecialty materials. The products are particularly characterized asbeing rimmed alkali metal alumino-silicate compositions which haveincreased opacity and structure, and unique morphology when comparedwith the starting clay material. Further, the brightness of theresulting product is substantially higher than the starting clay andcomparable or superior to various clay materials now used as reinforcingagents or functional fillers for paper, paints, plastics, and the like.It is truly unexpected that the opacity and brightness of the SAMScompositions would be significantly increased over the startingmaterials.

The alkali metal alumino-silicate products of the present invention alsohave unexpectedly high oil absorption characteristics, the oilabsorption in milliliters of oil per 100 grams of the SAMS productranging from about 40 to above 200 ml/100 g. This is quite remarkable inthat a hydrous clay of very low oil absorption of about 30 ml/100 g hasbeen transformed into a SAMS product of low to high structure (LS to HS)by the instant invention. For definition of structure, see Table I.

In this specification, the SAMS products are defined as structuredagglomerates wherein the primary particles comprise altered kaolin clayplatelets integrated with one or more adjacent areas of essentiallyamorphous alkali metal silicate base-kaolin clay reaction product, andwherein the primary particles of said SAMS products have attenuatedkaolin clay peaks in x-ray diffraction patterns from kaolin remnants inthe composition, and have the characteristic IR scan shown in FIGS. 3-6,and which are shown by TEM FIGS. 18-23 and 43.

The morphology and particle size of the structured agglomerates variesdepending on the specific reaction conditions and components employed.For example, the agglomerated SAMS products formed by the reaction ofalkali metal silicate and a fine particle size clay (like Hydragloss 90)usually have a spheroidal-like morphology, while those from a coarseparticle size delaminated clay (like Hydraprint) have a plateletmorphology. The products produced from sodium silicate and potassiumsilicate form rimmed materials having attenuated kaolin peaks, whereasthe products produced from lithium silicate form materials havingprotuberances on the surface and having attenuated kaolin peaks. By theterm "rimmed" is meant that the altered primary particles are comprisedof a core material having an integral border or outer edge material ofdifferent constitution from the core. The lithium silicate products haveprotuberances rather than rims, the protuberances being integral withthe core. The rim areas or protuberances appear to be not only x-rayamorphous but also electron diffraction amorphous, whereas the coreappears to have attenuated kaolin peaks on x-ray diffraction. Theprimary particles are generally in the form of lamella (irregular topseudo hexagonal shaped plates). The rim is an outer edge or borderwhich usually substantially encompasses the plate perimeter. The rimsand protuberances generally have an annular width or diameter of 20Å to1200Å, respectively, as measured from the outer surface of the particleto the beginning of the core area. By the term "amorphous" is meant thatthe material does not have a characteristic x-ray diffraction pattern.By the term "attenuated kaolin peaks" is meant that on x-raydiffraction, the material exhibits peaks located in the characteristicposition of kaolin, but which are depressed or weakened from the normalpeaks found for kaolin in x-ray diffraction. In this specification, theterm "functional pigment" means a non-color bearing material whichenhances desired properties in other materials and in some cases,reduces costs of the resulting mixture.

In the specification the term "hydrothermal" means that the reaction iscarried out under aqueous conditions of elevated temperatures andpressures of greater than atmospheric. The preferred temperatures rangefrom 140°-250° C. The preferred pressure conditions comprise pressuresranging from 50 to 360 psig. The reaction is conducted under conditionsof agitation, the speed of agitation depending on the reaction.

The specific SAMS products of this invention may be prepared by thefollowing reaction:

    Alkali metal silicate (B)+kaolin (C)=SAMS

The B/C ratio, which is the molar ratio of alkali metal (B) to molarratio of kaolin clay (C) in the batch composition, determines thevariety of SAMS compositions which can be produced by the teachings ofthe instant invention as can be seen in TEM FIGS. 18 through 23. A B/Cratio of less than 1.0 is the preferred embodiment of the instantinvention. Generally, at B/C ratios higher than 1.0, and especiallyhigher than 5.0 using sodium silicate, zeolites are in some casesproduced along with SAMS products, although SAMS of desired morphologyand preferred composition can also be produced without the presence ofzeolitic species by using special reaction conditions.

The preferred raw materials for the preparation of unique SAMScompositions are alkali metal silicate and kaolin clay. Typically, thealkali metal silicate is of the composition:

    M.sub.2 O:rSiO.sub.2

where M is the alkali metal and r is the number of moles of SiO₂ boundto a mole of alkali metal oxide. When M is sodium, the alkali metalsilicates are called sodium silicates and the value of r is the SiO₂/Na₂ O mole ratio. Typically, the alkali metal silicates used in theSAMS reaction have an r value of 1.0-6.0; the sodium silicates, thepreferred reactants, will have an r value of 1.0-4.0.

The kaolin clay used in the SAMS reaction may be represented by theformula Al₂ O₃ :2SiO₂ :2H₂ O. In calculation of the B/C ratio, the boundwater portion (LOI=13.4%) of the kaolin clay is accounted for in themolecular weight used for kaolin. The molecular weight of pure kaolin istherefore 258. Other ingredients which may be present as impurities,such as TiO₂ and Fe₂ O₃, are normally not included in the clay's MW, butare later accounted for in the % activity assigned to the starting claymaterial.

In this reaction, the alkali metal silicates which may be used aresodium silicate, potassium silicate and lithium silicate. In thereaction of kaolin clay with sodium silicate, there is produced a SAMSproduct whose primary particles have the characteristic core and rimcombination in all cases. In this product, the rimmed area is highlyconcentrated in silica vs. the core as determined by STEM/EDAX (ScanningTransmission Electron Microscopy/Electron Dispersive Analysis). Thistype of analysis determines the relative distribution of given elementswithin a material (i.e., it provides elemental mapping). In addition,this analysis indicates that sodium is generally well distributedthroughout the entire altered particle, both in the core and in the rim.This kind of product is obtained in all ratios of base to clay, exceptthat at high B/C ratios, the likelihood of zeolite formation increases.Therefore, in this invention, when the reaction includes that of kaolinclay with sodium silicate, it is preferred that the B to C ratio be nohigher than 5.0, preferably range from 0.1 to 5.0, and more preferablyrange from 0.25 to 0.9. Further, in B/C ratios of less than 1, theproduct has amorphous rims concentrated in silica and contains someresidual kaolin. In B/C ratios of greater than 1, the reaction is proneto zeolite formation of the crystalline type, such as the P type and Stype zeolite. Also, as the SiO₂ /Na₂ O ratio decreases in the sodiumsilicate, there is a tendency for increased zeolite formation in thisreaction. Therefore, the preferred SiO₂ /Na₂ O molar ratio in the sodiumsilicate is at least 2.0 and preferably is 2.5 to 3.3. The N brand andRU brand of commercially available sodium silicates (obtainable from PQCorp.) are preferred.

In the formation of SAMS products by the reaction of kaolin clay andpotassium silicate, the altered primary particles of the resulting SAMSproduct will exhibit rims in all cases, although the amorphous rimsformed in the potassium silicate SAMS product differs from the sodiumsilicate product in that the rims will be concentrated in both silicaand potassium. The acceptable B/C ratios using potassium silicate andkaolin range from 0.10 to 5.0, and more preferably from 0.1 to 0.9, andno substantial zeolite formation will be noted even at molar ratios ashigh as 5.0. As indicated above, rim alteration occurs during thesereactions and the rim material is concentrated in silica and potassium(versus the core material). The morphology of the potassium silicateagglomerates is usually similar to that of the sodium silicate product.However, as the ratio of SiO₂ /K₂ O increases in the potassium silicateused to react with the kaolin clay, the reactions are prone to producinga product whose agglomerate structure closely resembles a coral-likematerial. At lower ratios, the material is more similar to that producedfrom sodium silicate. The preferred SiO₂ /K₂ O ratios will range from2.8 to 3.9 with the commercial potassium silicate products KASIL 1, 6and 42 being preferred reactants.

The products produced from the lithium silicate and clay comprise a corematerial having protuberances or raised masses integral with the core.Electron diffraction analysis indicates that these protuberances aretotally amorphous, while the remaining platelet areas show the typicaldiffraction pattern for kaolinite. Most importantly, it should be notedthat the protuberances or raised masses did not form exclusively on theclay platelet edges, but appear in a more or less random fashion aboutthe platelets. Several pseudohexagonal clay platelets are still clearlyevident in the TEM photographs which indicates great heterogeneity ofreaction. Elemental mapping of the Si and Al content within a lithiumSAMS material, by STEM/EDAX analysis, has indicated that the alterationproduct (i.e., the protuberances) is much higher in silicon anddeficient in aluminum relative to the unaltered kaolinite regions.Elemental mapping of lithium was not possible because its atomic weightis below the detection limit of the instrument.

The SAMS compositions are produced by the reaction of clays and alkalimetal silicates under hydrothermal conditions. The clays which may beused include all kaolin-type clays, including crude, air-floated andwater-washed clays, as well as mixtures of clays and equivalentmaterials. Pure clays, as well as impure clays, may be used. Some of thepreferred clays are kaolin clays sold commercially under the trademarksOMNIFIL, HYDRASPERSE, HYDRAPRINT and HYDRAGLOSS. Other mineral sourcescorresponding to the silica-alumina values present in clays and alkalimetal silicates may be used. Sources of alumina such as alumina, sodiumaluminate, aluminum hydroxide or other aluminum sources may be usedwithout deviating from the spirit of the instant invention. Silicasources may include synthetic silica, reactive silica, sodium silicateor equivalent materials.

The alkali metal silicate can be any of the types of materials known tothe art, but preferably sodium silicate, potassium silicate, lithiumsilicate, or mixtures thereof, or compositions which can react to giveequivalent compounds should be used.

A critical feature of the invention is the molar ratio developed in thesystem between the amount of alkali metal silicate and the amount ofclay used. It is necessary to control the molar ratio of alkali metalsilicate to clay, otherwise a zeolitic crystalline product or mixturesof amorphous and crystalline species will be produced. The products ofthe present invention are typically rimmed compositions as depicted inTEM FIGS. 18 through 23. It is preferred that the molar ratio of alkalimetal silicate to clay be controlled to produce the desired SAMSproduct.

Further, the reaction of the present invention is carried out in anaqueous system using an aqueous slurry of the clay which is mixed withan aqueous solution of alkali metal silicate. The resulting clay andalkali metal silicate slurry preferably has a concentration of 1 to 20weight percent, preferably 5 to 15 percent.

In a preferred operation of the process, the aqueous slurry of thestarting clay material and the alkali metal silicate is formed, thesystem is closed and heat applied to gradually raise the temperature. Ingeneral, the pressure in the system will range from about 50 to 360 psigat temperatures ranging from about 140 to 250 degrees C. A specificallypreferred range of conditions is to operate the process at pressures of100 to 200 psig and temperatures of 164 to 194 degrees C. Thetemperatures are preferably correlated to the pressure such as thatprovided by steam. The reaction time is about 0.25 to 4 hours. Aftercompletion of the reaction, heat is removed and the mixture is allowedto cool, after which the system is opened, the product separated byfiltration or centrifugation, washed with water, and dried. Spray dryingis preferred at inlet temperatures of 1000° F. (538° C.) and outlettemperature of 250° F. (121° C.).

The resulting product may be characterized as having oil absorptionvalues ranging from about 40 to 220 ml/100 g. The surface area rangesfrom about 2 to 300 m² /g. More preferably, the product will have an oilabsorption value ranging from 80 to 160 ml/100 g and surface areasranging from 10 to 30 m² /g.

Particularly preferred SAMS products are those produced by reaction ofdelaminated clays with alkali metal silicates. A suitable delaminatedclay for reaction with the alkali metal silicate is that delaminatedclay sold commercially as Hydraprint by J. M. Huber Corporation.Hydraprint is a coarse particle size delaminated clay produced bydelamination of a cretaceous Middle Georgia Clay. The SAMS productformed by reaction of the alkali metal silicate and delaminated clay hasa platelet morphology which makes the product, referred to herein as a"platey" material, superior for light weight coating applications inthat it provides excellent sheet smoothness. These platey materials arealso especially useful for incorporation into plastics, such as highdensity polyethylene, since they provide excellent impact strength tothe polyethylene.

EXAMPLES

The following examples are presented to illustrate the invention, but itis not considered to be limited thereto. In the examples and throughoutthe specification, parts are by weight unless otherwise indicated.

EXAMPLE ONE Synthesis of Sams from Omnifil Clay

Water, 1,508 gallons (12,629 pounds), was added to a 2,500 gallonpressure reactor. To the water was added 101.3 gallons (1,458 pounds) ofa 67.7% solids kaolin clay slurry which is sold commercially as Omnifilby the J. M. Huber Corporation. This is a water-refined kaolin clayproduced from the East Georgia deposit having the properties shown inTable II. To the clay-water slurry was added 147.2 gallons of a freshwater sodium silicate solution (1,700 pounds) of 34.9% solids having aSiO₂ /Na₂ O molar ratio of 2.5. Under these conditions, the finalproduct solids will be approximately 10% and the batch composition willhave a base to clay molar ratio of approximately 0.75. The batchcomposition for the reaction can be expressed as

    Na.sub.2 O:1.33Al.sub.2 O.sub.3 :5.21SiO.sub.2 :278H.sub.2 O

and has an H/N (moles water/moles Na₂ O) ratio of 278, a S/N (moles SiO₂/moles Na₂ O) ratio of 5.2 and a S/A (moles SiO₂ /moles Al₂ O₃) ratio of3.9.

The batch was heated to a reaction pressure of 120 psig and atemperature of 172 degrees C. The mixture was allowed to react for onehour under continuous agitation. At the end of the one-hour reactiontime, the mixture was vented into a drop tank and the resulting mixturewas then filtered, washed and spray dried.

The product of Example One was evaluated and characterized by varioustest methods. The physical properties of the resulting synthetic alkalimetal alumino-silicate composition, or SAMS, representing the presentinvention are listed in Table II. The properties of the starting Omnifilclay control are also listed in Table II for comparative purposes.

                  TABLE II                                                        ______________________________________                                        SYNTHESIS OF SAMS FROM OMNIFIL CLAY                                                             SAMS from  Omnifil                                                            Omnifil Clay                                                                             Clay Control:                                    ______________________________________                                        Chemical Analysis,%                                                           TiO.sub.2         1.43       2.12                                             Fe.sub.2 O.sub.3  0.81       1.11                                             SiO.sub.2         52.82      44.33                                            Al.sub.2 O.sub.3  24.32      37.60                                            Na.sub.2 O        7.35       0.03                                             Physical Properties:                                                          Loss on Ignition, %                                                                             10.90      13.40                                            Pore Volume, cc/g                                                             (Mercury Intrusion)                                                                             3.10       1.10                                             Surface Area, m.sup.2 /g                                                                        19.8       20.0                                             pH (at 20% Solids)                                                                              10.8       6.5                                              Oil Absorption, ml/100 g                                                                        136        37                                               Valley Abrasion,                                                              (mg of wire loss) 8.7        10.5                                             Cation Exchange Capacity,                                                     meq/100 g NH.sub.4.sup.+, K.sup. +                                                              186        2-3                                              meq/100 g Ca.sup.+2, Mg.sup.+2                                                                  45         1-2                                              Brightness, %     86.1       82.0                                             Sedigraph Particle Size, %:                                                   +10 microns       0.5        1.8                                              +5 microns        3.0        4.0                                              -2 microns        58.5       89.0                                             -1 micron         34.0       82.9                                             -0.5 micron       15.0       68.1                                             ______________________________________                                    

EXAMPLE TWO Synthesis of Sams from Hydragloss 90 Clay

A second reaction was conducted in which 1,500 gallons (12,562 pounds)of water was used with 110 gallons (1,613 pounds) of a 70.1% solidskaolin clay slurry sold commercially as Hydragloss 90 by J. M. HuberCorporation having the properties shown in Table III. To the clay-waterslurry was added 112.4 gallons of a fresh water sodium silicate solution(1,298 pounds) of 34.9% solids having a SiO₂ /Na₂ O molar ratio of 2.5.Under these conditions, the final product solids will be approximately10% and the batch composition will have a base to clay molar ratio ofapproximately 0.50. The batch composition for the reaction can beexpressed as

    0.76Na.sub.2 O:1.52Al.sub.2 O.sub.3 :4.94SiO.sub.2 :278H.sub.2 O

and has an H/N of 366, an S/N of 6.5 and an S/A of 3.25.

The batch was heated to a reaction pressure of 120 psig and atemperature of 172 degrees C. The mixture was allowed to react for onehour under continuous agitation. At the end of the one-hour reactiontime, the mixture was vented into a drop tank and the resulting mixturewas then filtered, washed, and spray dried.

The product of Example Two was subjected to various tests. Set forthhereinafter in Table III are the physical properties of the resultingsynthetic alkali metal alumino-silicate composition, or SAMS,representing the present invention and the kaolin clay control fromwhich the SAMS composition was prepared.

                  TABLE III                                                       ______________________________________                                        SYNTHESIS OF SAMS FROM HYDRAGLOSS 90 CLAY                                                       SAMS from  Hydragloss 90                                    Chemical Analysis, %:                                                                           Hydragloss 90                                                                            Clay Control                                     ______________________________________                                        TiO.sub.2         0.51       0.94                                             Fe.sub.2 O.sub.3  0.83       0.98                                             SiO.sub.2         54.57      44.79                                            Al.sub.2 O.sub.3  27.95      38.37                                            Na.sub.2 O        6.75       0.03                                             Physical Properties:                                                          Loss on Ignition, %                                                                             10.71      13.86                                            Pore Volume, cc/g                                                             (Mercury Intrusion)                                                                             3.56       0.86                                             Surface Area, m.sup.2 /g                                                                        21.5       22.0                                             pH (at 20% solids)                                                                              11.2       6.8                                              Oil Absorption,                                                               ml/100 gm         156        43                                               Valley Abrasion,                                                              (mgs of wire loss)                                                                              6.8        7.5                                              Cation Exchange Capacity:                                                     meq/100 g - NH.sub.4.sup.+, K.sup.+                                                             183        2-3                                              meq/100 g - Ca.sup.+2, Mg.sup.+2                                                                48         1-2                                              Brightness, %     92.6       91.0                                             Sedigraph Particles Size, %:                                                  +10 microns       0.0        0.0                                              +5 microns        0.0        0.0                                              -2 microns        61.0       98.0                                             -1 micron         37.0       96.1                                             -0.5 micron       18.0       84.7                                             ______________________________________                                    

The following procedures were used for characterizing the data listed inTables II and III.

Chemical analyses (% TiO₂, % Fe₂ O₃, % SiO₂, % Al₂ O₃) were determinedby x-ray fluorescence. The sodium content (Na₂ O) of the final productwas determined by atomic absorption.

Ignition loss was determined by pre-drying the SAMS product to aconstant weight at 110 degrees C., heating to 925 degrees C. for onehour and cooling. Calculations of ignition loss were made as follows:##EQU3##

The pH was measured using a standard pH meter on a 20% solids (byweight) mixture of the product with water.

The specific surface area was determined by the nitrogen absorptionmethod described by Brunauer, Emett, and Teller (BET) in the "Journal ofthe American Chemical Society," Volume 60, page 309, published in 1938.A single point surface area determination was made on the SAMScompositions using outgassing conditions of three hours at 300 degreesC.

The oil absorptions of the beginning and end products from Examples Oneand Two were determined by the oil rub-out method. This method is basedon a principle of mixing linseed oil with the product by rubbing with aspatula on a smooth surface until a stiff putty-like paste is formedwhich does not break or separate. By measuring the quantity of oilrequired to give a paste mixture which will curl when spread out, onecan calculate the oil absorption value of the product--a value whichrepresents the volume of oil required per unit weight of product tosaturate the product sorptive capacity. Calculation of oil absorptionvalue was done as follows: ##EQU4##

Cation exchange capacity was determined by adding the products (0.25g-weighed to 0.1 mg) to tarred, screw-cap, 15-ml centrifuge tubes. Thesamples were centrifugally washed three times with 10-ml of a 0.5Msolution of the saturating cation. The samples were subsequently washedfive times with a 0.05M solution of the saturating cation. Following thefifth washing and decantation of the supernatant solution, the tubeswere capped and weighed. This weight, less the sample weight, representsthe amount of excess 0.05M saturating solution. The occluded (soluble)and exchangeable cations were then displaced by washing three times witha 0.5M solution of a displacing cation, collecting the washings in 100ml volumetric flasks. The amount of the saturating cation was determinedby atomic absorption spectroscopy with the exception of ammonium (NH⁺ ₄)which was determined by potentiometric titration. The net amount ofexchangeable cations was calculated by subtracting the amount ofsoluble, occluded cations (wet weight times 0.05M) from the totalanalyzed amount.

Brightness measurements were performed by the standard TAPPI (TechnicalAssociation of Pulp and Paper Industry) procedure T-534 pm-76, publishedin 1976.

Particle size was determined using a Sedigraph 5000 ET Particle SizeAnalyzer from Micromeritics Instrument Corporation, Norcross, Georgia.This instrument uses a sedimentation technique which measures theparticle size distribution as a modification of Stokes Law. Theprocedure is described in "Instrument Manual-Sedigraph 5000 ET ParticleSize Analyzer," published May 3, 1983.

The Fourier Transform-Infrared spectroscopy (FT-IR), transmissionelectron microscopy (TEM), scanning electron microscopy (SEM and x-raydiffraction (XRD) scans were determined using standard techniques.

From the above data, it will be seen that the process of the inventionyields new products having novel combinations of physical and chemicalproperties.

As shown in Tables II and III, the synthetic alkali metalalumino-silicates of the present invention prepared from the commercialkaolin clays exhibit substantial improvements in cation exchangecapacity, oil absorption and brightness. This is quite astonishing inthat a hydrous clay product of relative worth has been converted into asynthetic product of greatly added value by the relatively simpleprocedure of the present invention. Of particular interest is thesignificant improvement in oil absorption which indicates that a higherstructure product has been formed as a result of this invention.

The infrared spectra of the SAMS compositions of Examples One and Twoare compared with the infrared spectra of their respective base clays inFIGS. 3 and 4, respectively. As anyone skilled in infrared spectroscopycan see, the IR spectra of SAMS compositions are considerably differentfrom those of their respective base clays, especially in the 1200-875wavenumber (cm⁻¹) absorption region. The Si-O stretching band between1200 and 950 wavenumbers is much broader and less well defined for theSAMS than for the control clays, indicating that the compositionscontain considerable amorphous material. In addition, the aluminum O-Hvibration band between 950 and 875 wavenumbers are essentially identicalfor the SAMS compositions and their base clays, with the SAMScomposition showing only a slight decrease in peak intensity.

In FIG. 1, the FT-IR scan of the SAMS composition of Example Two iscompared with the FT-IR scans of an amorphous synthetic silicate (Zeolex23), a calcined kaolin (Hycal) and an amorphous synthetic silica (Hi-Sil233). The spectrum of the SAMS composition is similar to those of Zeolex23, Hycal, and Hi-Sil in the 1200-950 wavenumber Si-O stretching regionbut is considerably different in the 950-400 wavenumber region. Only theSAMS composition has the aluminum O-H vibration band between 950 and 875wavenumbers.

In FIG. 2 the FT-IR spectrum of the SAMS composition of Example Two iscompared with the spectra of zeolites A, X, Y and analcime. The spectrumof the SAMS composition differs from the spectra of the crystallinezeolites across the entire IR spectrum. The Si-O band (1200-950 cm⁻¹)for the zeolites is very sharp, indicating good crystallinity, whilethat of the SAMS is broad. Again, only the SAMS spectrum shows thealuminum O-H vibration band.

Based on the infrared spectra, it must be concluded that the SAMScompositions of the instant invention are unique entities that differsignificantly from the starting clays as well as from crystalline andamorphous zeolites, synthetic silicates and synthetic silicas of priorart.

The unique characteristics of the synthetic alkali metalalumino-silicates (SAMS) of the instant invention can also be seen bycomparing the SEM photographs of the SAMS compositions of Example Oneand Two (FIGS. 13 and 14, respectively) with those of prior art zeolitesA, X, Y and analcime (FIGS. 9, 10, 11 and 12, respectively). The SEMphotographs show the prior art zeolites to be large, well crystallizedmaterials, while the SAMS compositions appear to be structuredagglomerates composed of small flat platelets.

The TEM photographs of the SAMS compositions of Example One and Two,prepared by following the preferred teachings of the instant invention(B/C less than 1.0), and the photographs of SAMS compositions preparedat B/C ratios equal to and greater than 1.0 can be seen in FIGS. 18through 23, respectively, and show the SAMS to be unique in compositionand morphology. The TEM photographs (FIGS. 18-23) show the SAMScompositions to contain remnants of altered clay platelets having anintegrated rimmed area of alkali metal silicate-kaolin reaction product.The rimmed area can be shown by electron diffraction (ED) to beamorphous and non-diffracting. The SAMS compositions shown in FIGS.18-23, are unique and considerably different in appearance than thestarting Omnifil and Hydragloss 90 clay (FIGS. 24 and 25, respectively),as well as the prior art silicates, silicas, and calcined clays shown inFIGS. 15-17.

When comparing the x-ray diffraction patterns of the SAMS compositionsof Examples One, Two and Five (FIGS. 33-36) with the XRD patterns of thestarting clays (FIGS. 37 and 38), only attenuated kaolin peaks from thekaolin remnants can be observed. The XRD patterns of the SAMScompositions are also obviously different than the XRD patterns of theprior art zeolites, silicates, silicas, and calcined clay shown in FIGS.26-32.

END-USE APPLICATIONS

The novel SAMS products of the present invention were evaluated in avariety of end-use application compositions. Truly remarkableperformance of SAMS products are documented below.

1. Paper Coating Compositions

The SAMS product of Example Two derived from Hydragloss 90 clay wasevaluated in a typical paper coating composition and evaluation data areshown in Table IV.

A coating is applied to a paper substrate primarily to improve printingquality, although improvements in optical properties such as brightnessor sheet gloss may also be obtained. The SAMS product made fromHydragloss 90 in Example Two was included at low levels in coatingcompositions and compared with a composition using only a commercialgrade of delaminated kaolin clay (Hydraprint), and a compositioncontaining the delaminated clay and a low level of a commerciallyavailable, high brightness, low abrasion calcined clay (Hycal), in anapplication for lightweight publication grade paper. The end-use of thisparticular paper and its coating formulation was in the art of printingby the rotogravure method. Coatings were applied to a commerciallyproduced paper substrate at a coat weight typical to the grade using theKeegan Laboratory Blade Coater. Following supercalendering, coatedsheets were tested for optical properties in accordance with thefollowing TAPPI (Technical Association of Pulp and Paper Industry)standards:

T-452: Brightness of Pulp, Paper and Paperboard

T-480: Specular Gloss of Paper and Paperboard at 75 degrees

Rotogravure printability was determined using the Diamond National PrintSmoothness Tester. The procedure followed is to coat, calender and printpaper samples by the rotogravure method with a series of lines composedof dots. The dots are the result of printing cells engraved on therotogravure printing cylinder, each of identical diameter and depth. Thenumber of dots which do not transfer to the sheet is determined, withthe greater number of missing dots being interpreted as poorerrotogravure printability.

As noted from Table IV, when used at one-half the loading level ofcalcined clay, the product of the current invention unexpectedlyproduced a sheet of equivalent rotogravure printability, and clearlysuperior to that where only delaminated clay was used. Thus, one part ofthe product of the current invention can replace two parts of calcinedclay resulting in substantial cost savings for those skilled in the artof paper coating. Furthermore, when used at an equal loading level withthe expensive calcined clay, the SAMS product of this invention yieldeda sheet of comparable optical properties, and clearly superiorrotogravure printability.

                                      TABLE IV                                    __________________________________________________________________________    PAPER COATING COMPOSITIONS CONTAINING SAMS                                                      90%    90%    95%                                                             Hydraprint                                                                           Hydraprint                                                                           Hydraprint                                                      10%    10%    5%                                                       100%   Calcined                                                                             SAMS from                                                                            SAMS from                                                Hydraprint                                                                           Clay   Example Two                                                                          Example Two                                   __________________________________________________________________________    Brightness, %                                                                            68.2   69.2   69.0   68.7                                          75 Degree Gloss, %                                                                       43.7   45.0   45.5   44.0                                          Missing Dots/Sheet*                                                                      31     22     15     23                                            __________________________________________________________________________     *Diamond National smoothness test                                        

2. Fine Paper Filler Compositions

Pigments are used as fillers in paper sheets for many reasons, amongwhich are the improvement of optical properties such as brightness andopacity. The most efficient pigment for this purpose is titaniumdioxide; however, its price is prohibitive for its sole use in thisapplication. A class of pigments, known as titanium dioxide extenders,are less expensive, but still quite costly. When used in combinationwith titanium dioxide, these pigments allow for reduced titanium dioxideuse while maintaining optical properties. Two pigments from this groupwhich are quite effective are calcined kaolin clay and amorphous sodiumsilico-aluminate (Hydrex) pigments. The SAMS product made fromHydragloss 90 in Example Two was substituted directly for the titaniumdioxide extender pigments, calcined clay (Hycal) and sodiumsilico-aluminate (Hydrex), in a filler furnish containing 50% No. 2grade clay (Hydrasperse), 17% titanium dioxide (DuPont LW), and 33%extender pigment. Handsheets were formed using the British StandardHandsheet Mould, weighed to assure uniform basis weight, and testedaccording to the prescribed TAPPI standards:

T-425: Opacity of Paper

T-452: Brightness of Pulp, Paper, and Paperboard

Additionally, the scattering and absorbance coefficients (S and K,respectively) were determined using the Kubelka-Munk equation. The valueK/S was then determined, and presented as the scattering efficiency.Greater efficiency is noted as the K/S value approaches zero. Thecomparative evaluation data of SAMS and other extender pigments used inthe paper filler composition is given in Table V.

It will be noted from Table V that the product of the current inventioncompares favorably to the expensive extender pigments in all parametersat each filler loading level. This is quite surprising in that the SAMSproducts of the present invention can be a match for the most expensiveextender pigments normally used by the paper industry.

                  TABLE V                                                         ______________________________________                                        FINE PAPER FILLER COMPOSITIONS CONTAINING SAMS                                                                   Light                                                                         Scattering                                                    Bright-         Efficiency,                                             Filler,                                                                             ness,   Opacity,                                                                              K/S                                                     %     %       %       × 10.sup.-2                          ______________________________________                                        Unfilled Control                                                                             0       82.5    71.8  1.87                                     50% No. 2 Clay 2       84.3    74.4  1.46                                     17% Titanium Dioxide                                                                         4       85.4    78.5  1.25                                     33% Calcined Clay (Hycal)                                                                    8       86.0    81.2  1.14                                     50% No. 2 Clay 2       84.8    73.9  1.36                                     17% Titanium Dioxide                                                                         4       85.5    78.2  1.23                                     33% Hydrex     8       86.2    81.6  1.10                                     50% No. 2 Clay 2       85.0    75.2  1.32                                     17% Titanium Dioxide                                                                         4       85.4    78.1  1.25                                     33% SAMS from Example                                                                        8       86.0    81.5  1.14                                     Two                                                                           ______________________________________                                    

3. Newsprint Paper Compositions Containing Sams

Another function of fillers in uncoated paper is to retard the amount ofink which penetrates the sheet, causing discoloration to the other sideof the paper. This problem, frequently referred to as "printshow-through" or "print through," is generally encountered in newspaperprinting. Improvement in this property is of more concern as qualitystandards for newsprint and similar grades continue to tighten.

The SAMS products made from Omnifil and Hydragloss 90 clays in ExamplesOne and Two are compared with their respective starting materials, to acommercial grade of high brightness, low abrasion calcined kaolin clay(Ansilex), and to a high brightness sodium silico-aluminate (Zeolex 23P)in their ability to reduce show-through. Handsheets were prepared fromcommercial newsprint pulp using a Noble and Wood sheet machine, andtested in accordance with the following TAPPI standards:

T-410: Basis Weight of Paper and Paperboard

T-425: Opacity of Paper

T-452: Brightness of Pulp, Paper and Paperboard

Additionally, printing tests were performed at standard conditions oftemperature and humidity on a Universal No. 1 Vandercook Proof Pressusing a standard newsprint ink and a printing plate mounted type high.The plate was designed for printing a solid area 4 inches by 41/4inches. Prints were made with 4 mils impression by press bed adjustment,and the ink pickup determined by weighing each sheet before and afterprinting. Variations in printing and ink pickup necessitated printingeach ash level at three ink levels, and obtaining printing values atexactly 2.0 g/m² ink pickup graphically.

Printed sheets were conditioned overnight at 73 degrees F. and 50%relative humidity prior to evaluation by a brightness tester at 457 nmon the side opposite the printing surface. Show-through was determinedin accordance with Larocque's equation: ##EQU5##

Comparative data on the newsprint evaluation of SAMS and other expensiveextender pigments are given in Table VI.

                                      TABLE VI                                    __________________________________________________________________________    NEWSPRINT EVALUATION OF SAMS AND                                              OTHER EXTENDER PIGMENTS                                                                Filler                                                                            Basis                                                                              TAPPI     Show-Through                                      Filler   Level,                                                                            Weight,                                                                            Bright-                                                                            Opacity,                                                                           @ 2 g/m.sup.2                                                                      Reduction,                                   Pigment  %   #/ream                                                                             ness, %                                                                            %    Ink, %                                                                             %                                            __________________________________________________________________________    Unfilled None                                                                              30.6 52.9 85.1 10.8 --                                           Omnifil (Control)                                                                      2   30.3 52.9 85.1 12.6 (16.7)                                                4   30.4 60.0 85.5 11.7 (8.3)                                        Hydragloss 90                                                                          2   30.5 59.4 85.1 13.1 (21.3)                                       (Control)                                                                              4   30.1 60.6 85.4 12.8 (18.5)                                       Ansilex  2   29.8 60.5 85.6 10.8 0                                            (Calcined Clay)                                                                        4   30.1 62.0 87.4 9.1  15.7                                         Zeolex 23P                                                                             2   30.4 60.2 85.5 9.1  15.7                                         (Sodium Sico-                                                                          4   30.4 61.3 86.5 6.4  40.7                                         Aluminate)                                                                    SAMS from                                                                              2   30.3 59.9 86.3 9.6  11.1                                         Example One                                                                            4   30.7 61.9 88.0 7.0  35.2                                         SAMS from                                                                              2   30.3 60.5 86.4 8.7  19.4                                         Example Two                                                                            4   30.6 62.0 88.5 6.8  37.0                                         __________________________________________________________________________

It is seen in Table VI that the SAMS product from Example Two performsas well as the calcined clay and superior to the other pigments inbrightness improvement, and is also the superior pigment in opacityimprovement. The SAMS product from Example One is surprising in itsperformance as well. Its opacity is second only to the product made fromExample Two, exceeding both of the other higher brightness pigments,Ansilex and Zeolex 23. Concerning show-through, it can be noted fromTable VI that the use of the starting hydrous clay materials (Omnifiland Hydragloss 90) actually result in more show-through than observedwith the unfilled sample. The use of calcined clay, while improvingshow-through modestly at 4% filler loading, leaves the sheet unchangedfrom unfilled at the 2% filler level. When the products of the currentinvention are substituted directly at the 2% filler level for the Zeolex23 pigment, that pigment being the product of choice for this purpose incommercial applications, the results were indeed surprising. The SAMSproduct from Example Two actually surpasses the Zeolex 23 pigment, whilethat made in Example One is only slightly deficient. Although theproducts of the current invention are slightly less efficient than theZeolex 23 at the higher loading level, they are clearly superior totheir starting inexpensive clay controls and to the expensive calcinedclay. Furthermore, due to the high cost of the Zeolex 23 pigment, it canbe easily shown that the cost per unit of strike-through reduction forthe products of the present invention is much more favorable than thatof the Zeolex 23. Thus, if used at quantities sufficient for equalstrike-through reduction, the products of the current invention wouldprovide significant cost savings in this application.

4. LATEX PAINT COMPOSITIONS CONTAINING SAMS

In the past, functional extender pigments were primarily used in paintas adulterants to replace more expensive prime pigments and binders;thereby resulting in a lower cost paint formulation. However, with theadvent of new and improved functional extender pigments, the use ofthese pigments has grown. They are now incorporated into the paintformulations to improve optical properties such as whiteness, hidingpower/contrast ratio, and tinting strength.

In this regard, the SAMS product made from Hydragloss 90 in Example Twowas compared with the kaolin clay from which the SAMS composition wasprepared and leading commercial pigments used as functional extenders inlatex-based paints.

Whiteness (directional reflectance, Y-value) and contrast ratio weredetermined by making drawdowns of the paints containing control clay(Hydragloss 90), the SAMS product from Example Two made from Hydragloss90, a commercial extender pigment (Hi-Sil 422), and calcined clay (Huber90C), on opacity charts having a simple combination of black and whiteareas large enough for reflectance measurements. Such charts aresupplied by the Leneta Company, Ho-Ho-Kus, New Jersey. Directionalreflectance, Y values, are determined using a Gardner XL-20 TristimulusColorimeter on the dried paint films over both the black and white areasof the charts. Whiteness is reported as the Y value determined over thewhite area. Contrast ratio is determined by dividing the Y values overblack areas by the Y values over the white areas of the charts and is ameasure of the relative opacity of the paint.

Relative tint strength was determined by blending 1%, by weight, of alamp black colorant to each paint, making drawdowns on the opacitycharts and then determining Y values of the dried paint films over thewhite areas of the charts. Relative tint strength is reported as this Yvalue.

Comparative paint performance results of unique SAMS products and otherexpensive extender pigments are contained in Table VII.

                  TABLE VII                                                       ______________________________________                                        LATEX PAINT EVALUATION OF SAMS                                                AND OTHER PIGMENTS                                                                           Whiteness                                                                     (Directional        Relative                                                  Reflectance,                                                                             Contrast Tint                                       Pigment        Y-Value, %)                                                                              Ratio    Strength, %                                ______________________________________                                        Hydragloss 90, Control                                                                       87.9       .944     38.8                                       SAMS from Example Two                                                                        88.8       .958     41.0                                       Hi-Sil 422     88.7       .947     40.8                                       Huber 90C      88.6       .949     40.5                                       ______________________________________                                    

Regarding Table VII, it will be noted that the control clay Hydragloss90 and the commercial products, Hi-Sil 422 (fine particle hydratedsilica pigment), and Huber 90C (high brightness, low abrasion calcinedclay) are compared with the Hydragloss 90 product of Example Two withrespect to whiteness, contrast ratio and tint strength. The variouspigments were evaluated in a typical high pigment volume concentration,interior, flat, vinyl acrylic paint. Pigmentation of the paint consistedof 17.6% rutile titanium dioxide, 19.6% standard calcined clay, 58.8%coarse particle-size calcium carbonate, and 4.0% of the evaluatedpigment. It will be noted from Table VII that the SAMS product of thisinvention produces significant improvements over the kaolin clay fromwhich the product of this invention was prepared in whiteness, contrastratio and relative tint strength. Even more unexpectedly, the product ofthis invention gave an enhanced contrast ratio and superior tintstrength to the more costly functional extender, Hi-Sil 422.

Additionally, as can be seen from Table VII SAMS products of the presentinvention exhibit the best whiteness, contrast ratio (or hiding power)and tint strength when compared with expensive commercial extenderpigments. It is truly remarkable how the inexpensive starting clay hasbeen converted into a functional product SAMS by the teachings of thepresent invention.

5. NATSYN 2200 RUBBER COMPOSITIONS CONTAINING SAMS

Fillers are added to rubber compounds to provide reinforcement or act asa diluent. Small particle substances are considered to reinforce rubberif they give to the vulcanizate high abrasion resistance, high tear andtensile strength, and some increase in stiffness. The most importantcharacteristic required of a reinforcement agent is a fine particlesize. Among non-black fillers, the best modulus and tensile strength areproduced by precipitated silica (Hi-Sil), followed by synthetic sodiumsilico-aluminate (Zeolex). Fine particle size fillers that areapproximately spherical in shape, such as many silicas, give better tearresistance and abrasion resistance to rubber than do needle-shaped orplate-like particles.

SAMS from Examples One and Two were evaluated in rubber compositions andtheir performance compared with the more expensive fine particleprecipitated, hydrated amorphous silica product, Hi-Sil 233.

The rubbers which can be employed in the invention include both naturaland synthetic rubbers. Exemplary of suitable synthetic rubbers arestyrene-butadiene, butyl rubber, nitrile rubber, neoprene rubber,polybutadiene, polyisoprene, ethylene propylene, acrylic, fluorocarbonrubbers, polysulfide rubbers, and silicone rubbers. Mixtures ofcopolymers of the above synthetic rubbers can be employed alone or incombination with natural rubber. The most preferred rubbers are naturalrubber, polyisoprene, nitrile rubber, styrene-butadiene, and mixturesthereof.

The SAMS product made from Hydragloss 90 in Example Two was evaluatedagainst a fine particle precipitated, hydrated amorphous silica product(Hi-Sil 233) in a non-black synthetic polyisoprene (Natsyn 2200) rubberformulation.

The SAMS and silica products were used at a 38-40 part level per 100parts rubber. The filler products were compared with respect to modulusand tensile strength (ASTM D1456), heat buildup (rectangular blockoscillating horizontally between two weights), compression set (ASTM395--ability of rubber compounds to retain elastic properties afterprolonged action of compressive stresses), and tear strength (ASTM 624).

Evaluation results of the reinforcing properties of SAMS and acommercial expensive synthetic silica, Hi-Sil 233, are listed in TableVIII.

                  TABLE VIII                                                      ______________________________________                                        NATSYN RUBBER REINFORCING PROPERTIES OF SAMS                                                        SAMS from                                                              Hi-Sil 233                                                                           Example Two                                             ______________________________________                                        300% Modulus, psi*                                                                             460      630                                                 Tensile Strength, psi*                                                                         2,850    2,870                                               Heat Buildup, Degrees F.                                                                       267      136                                                 Tear Strength, ppi                                                                             140      155                                                 Compression Set, %                                                                             41.6     23.2                                                ______________________________________                                         *10 Minute cure                                                          

It will be noted from the Table VIII that the SAMS product of thisinvention is superior to the amorphous silica product in modulus,compression set, and heat buildup, where the silica product has twicethe heat buildup when compared with SAMS products of the presentinvention. It is truly remarkable that the inexpensive clay has beenconverted into a unique functional SAMS composition. This uniqueproperty of low HBU (heat buildup) causes the product to have particularutility for use in tires, hoses, and belts where lower heat generationfrom friction will substantially prolong the longevity of theseproducts. In this regard, the synthetic alkali metal alumino-silicatesof this invention can also be used gainfully in elastomeric applicationswhere exposure to high temperatures can cause severe deterioration ofstandard elastomeric systems.

The tire industry has been looking for a reinforcing filler which willprovide low heat buildup in rubber formulations. As data clearly showsin Table VIII, the heat buildup imparted by SAMS of the presentinvention is almost one-half that of the commercial expensive silica,Hi-Sil 233. The control structure of the unique SAMS compositions isresponsible for providing excellent rubber reinforcing properties.

6. GIANT TIRE RUBBER COMPOSITIONS CONTAINING SAMS

The SAMS products made from Omnifil and Hydragloss 90 in Example One andTwo were evaluated against a fine particle, precipitated, hydratedamorphous silica product (Hi-Sil 233) in an off-the-road giant tiretread natural rubber formulation containing N220 carbon black. The SAMSand silica products were used at a 15 part level and the N220 carbonblack at a 40 part level per 100 parts of rubber.

The filler products were compared with respect to modulus, tensilestrength, tear strength, heat buildup, and a flex fatigue failure test(ASTM D1052--Ross flexing machine that allows a pierced rubber specimento bend freely over a rod through an angle of 90 degrees for the numberof cycles required for specimen failure). It will be noted from the testresults of Table IX that the SAMS products of this invention fromOmnifil and Hydragloss 90 are equal or superior to the high-pricedamorphous silica product in modulus, tensile strength, tear strength,heat buildup, and flex fatigue. Of particular interest is the startlingincrease in flex fatigue property which should be very important inelastomeric systems in which a great deal of bending and stretchingstresses are involved, such as shock suppressors, hoses and tubing,bushings, etc.

By examining the evaluation data in Table IX, it can be clearly seenthat the unique SAMS products provide excellent flex fatigue protectionto rubber compositions when compared with the expensive commercialsilica products, Hi-Sil 233.

It is quite remarkable that the inexpensive clay products have beenconverted to more useful value-added materials called SAMS by theteachings of the instant invention. The performance properties of SAMSin rubber compositions are unique and quite unexpected. It appears thatthe novel SAMS compositions of the present invention are controlledstructures in nature and provide optimum filler-polymer interaction inrubber compositions.

                  TABLE IX                                                        ______________________________________                                        GIANT TIRE RUBBER REINFORCING                                                 PROPERTIES OF SAMS                                                                             SAMS From                                                                Hi-Sil 233                                                                           Example One                                                                              Example Two                                     ______________________________________                                        300% Modulus, psi*                                                                          1,360    1,490      1,500                                       Tensile Strength, psi*                                                                      3,700    3,780      3,870                                       Tear Strength, ppi                                                                          605      575        625                                         Heat Buildup, Degrees F.                                                                    278      267        260                                         Flex Fatigue, (Cycles                                                                       471      835        666                                         To Failure × 1000)                                                      ______________________________________                                         *90 Minutes Cure                                                         

7. COLOR CONCENTRATE PLASTICS COMPOSITIONS

Pigments, fillers and extenders are mixed with plastics resins toproduce color concentrates. Titanium dioxide and colored pigments arewidely used to produce pigmented plastics concentrates.

A study was undertaken in which a 50% TiO₂ concentrate was produced inhigh density polyethylene (HDPE) resin. This concentrate was called thecontrol concentrate.

The SAMS product from Example Two was used to extend TiO₂ of the controlconcentrate by replacing 10 and 20% by weight of the TiO₂ with SAMS. Thefollowing plastic compositions were used to produce the variousconcentrates.

    ______________________________________                                        Ingredients                                                                              Control   Concentrate A                                                                            Concentrate B                                 ______________________________________                                        HDPE       50        50         50                                            R-101 (TiO.sub.2)                                                                        50        45         40                                            SAMS (from --        5          10                                            Example Two)                                                                  ______________________________________                                    

The control and concentrates A and B containing 5% and 10% SAMS werecompounded in the 3# Farrel Banbury. Each sample was then granulated,extruded and pressed out for testing. The optical properties of thevarious concentrates were then evaluated.

The opacity and brightness of the control and SAMS containingconcentrates are listed in Table X. This study suggests that SAMS of theinstant invention can be used in color concentrates without loss inopacity and brightness.

Data are listed in Table X.

                  TABLE X                                                         ______________________________________                                        PLASTIC COLOR CONCENTRATES CONTAINING SAMS                                                       Elrepho                                                                       Brightness,                                                                             Opacity,                                         Concentrate        %         %                                                ______________________________________                                        TiO.sub.2 - Control                                                                              89.1      0.980                                            Concentrate A (w/SAMS)                                                                           91.8      0.985                                            Concentrate B (w/SAMS)                                                                           91.4      0.990                                            ______________________________________                                    

8. DEFOAMER COMPOSITIONS

Defoamer compositions are used to suppress foam formation in the paper,paint, food and many specialty industries.

Defoamer compositions were prepared by using the following formulations:

    ______________________________________                                        Ingredients        Parts (by weight)                                          ______________________________________                                        Dow 3011 Antifoam Chemical                                                                       4.0                                                        Ammonium Carbonate 1.0                                                        Mineral Oil        200.0                                                      HG 90 or SAMS      10.0                                                       (from Example Two)                                                            ______________________________________                                    

The mineral oil called for in the above formulation was weighed out andplaced in a stainless steel cup. Control clay or SAMS from Example Twowas hand-mixed with the mineral oil. This mixture was dispersed on aHockmeyer mixer for five minutes at 2300 rpm speed. The antifoamchemical was then added, followed by ammonium carbonate. The wholecomposition was mixed for an additional three minutes.

The contents of the stainless steel cup were transferred into a 500 mlflask and heated at 80 degrees C until the foaming stopped. Thetemperature was then increased to 105 degrees C and the compositionmaintained at this temperature for two hours. The flask was removed fromthe hotplate and after cooling, the contents were transferred to aone-half pint can for storage. At this point the defoamer composition isready for evaluation.

The defoamer composition was checked for foam suppression properties.One liter of black kraft liquor (15% solids) was poured into a 2500 mlburette which was hooked up to a gravity feed circulating pump flowingat the rate of five liters per minute.

While the black liquor was at rest, 0.02 g (or two drops) of thedefoamer composition was added to the burette. The pump and a stop watchwere simultaneously started to record the time it takes the foam heightto reach six inches from starting point of liquor at rest. A defoamercomposition which suppresses the foam from reaching a six-inch heightfor the longest time is considered the best defoamer compound.

Defoamer efficiency data are given in Table XI.

                  TABLE XI                                                        ______________________________________                                        DEFOAMER COMPOSITIONS                                                         Defoamer Compositions                                                                             Six-Inch Suppression Time                                 ______________________________________                                        Compound w/HG-90 - Control                                                                        27        seconds                                         Compound w/SAMS     233       seconds                                         (from Example Two)                                                            ______________________________________                                    

From data in Table XI, it is clear that SAMS makes an excellent defoamerwhen compared with the starting clay. In fact, the defoaming efficiencyof SAMS from Example Two is about 762% better than the Hydragloss 90control. It is truly remarkable that the present invention has convertedthe Hydragloss 90 clay into a valued added SAMS product of uniqueefficiency for use in defoamer compositions.

9. DRY-UP LIQUID/CARRIER COMPOSITIONS

Liquids, active substrates and rubber chemicals are dried up on fineparticle carriers. The dry, free flowing powders are produced by addingthe powder to the liquid while mixing in a Hobart mixer until a dry,free-flowing powder is produced. From the weight of the liquid carriedon a carrier solids, one can calculate the carrying capacity of thecarrier powder.

The SAMS product from Example Two was compared with the control clay(Hydragloss 90) in terms of the carrying capacity of mineral oil andFlexon (Exxon) processing oil. These liquids were converted to dry,free-flowing powders with the carrying capacity expressed as the percentby weight of liquid (% active) present. The carrying capacity data isgiven in Table XII.

                  TABLE XII                                                       ______________________________________                                         CARRYING CAPACITY OF SAMS                                                    ______________________________________                                        Liquid: Mineral Oil                                                           Carrier Powder     % Active                                                   ______________________________________                                        Control Clay       10                                                         SAMS from Example Two                                                                            58                                                         ______________________________________                                        Liquid: Flexon Oil                                                            Carrier powder     % Active                                                   ______________________________________                                        Control Clay       10                                                         SAMS from Example Two                                                                            60                                                         ______________________________________                                    

From data in Table XII, it can be readily seen that SAMS of the instantinvention has excellent carrying capacity when compared with the claycontrol. It is quite remarkable that clay has been converted into thefunctional carrier SAMS by the teachings of the instant invention.

10. PAINT COATING COMPOSITIONS

In order to provide protection and to produce a pleasing appearance, avariety of surfaces, such as wood, metal fabric, paper, or plastics, arecoated with clear flatting compositions containing dispersed orsuspended particles of a flatting agent which reduces the gloss or sheenof the coating and the coated substrate, preferably withoutsubstantially reducing the transparency of the flat coating. Forexample, wood finishes which serve to protect the surface againstabrasion and stain, yet do not conceal the beauty of the grain, are madeto simulate desirable hand-rubbed finishes by incorporating flattingagents therein which normally are dispersed fine particles of suchmaterials as silicas. The best effects are obtained with silicas ofuniform particles size down to the submicron range. Small size anduniformity are necessary to achieve a smooth coating without whitespecks or without a graying effect which would detract from theappearance of the coating.

For paint flatting application, 10 grams of SAMS from Example Two of theinstant invention was mixed with 350 grams of nitrocellulose lacquer(conforming to Military specification MIL-L-10287A-amendment 2, Type II,of issue 27, Aug. 1959), and mixed for three minutes using the low speedsetting of the Hamilton Beach #30 mixmaster. The lacquer containingdispersed SAMS was tested for Hegman fineness of grind.

The lacquer containing dispersed SAMS from Example Two was evaluated forpaint flatting properties. A drawdown was made on Carrara glass using a#34 wire coatings application rod. The Carrara glass drawdowns wereallowed to dry for 45 minutes under dust-free conditions. Using theabove method, drawdowns were also made by using a control syntheticsilica normally used in this application.

Using the Gardner multi-angle gloss meter, the gloss and sheen values ofthe various drawdowns were measured at 60 degrees and 85 degrees,respectively. These values were compared with measured values obtainedwhen a control silica was dispersed in the lacquer.

SAMS of the present invention result in cleaner Hegman grinds andexhibit better clarity when dispersed in the lacquer.

Flatting data listed in Table XIII suggests that the novel SAMS of thepresent invention exhibit lower gloss and sheen values than the controlsilicas. Lower gloss and sheen values are preferred and advantageous forpaint flatting applications.

                  TABLE XIII                                                      ______________________________________                                        PAINT FLATTING EVALUATION                                                                       60 Degree 85 Degree                                         Flatting Agent    Gloss     Sheen                                             ______________________________________                                        SAMS (Example One)                                                                              10        21                                                SAMS (Example Two)                                                                              8         16                                                Control Silica    15        45                                                (Zeothix 95)                                                                  ______________________________________                                    

A close examination of the data in Table XIII clearly shows the SAMScompositions of the instant invention as having superior flattingproperties compared with the synthetic silica control. It is quiteremarkable that clay has been converted into a value added functionalproduct by the teachings of the instant invention.

11. DETERGENT COMPOSITIONS

Typical home laundry detergents are generally formulated as a 50-60%solids slurry and spray dried to give the familiar powdered products. Atypical home laundry detergent consists of the following ingredients:

    ______________________________________                                        Ingredient        Percent, by weight                                          ______________________________________                                        Sodium Tripolyphosphate                                                                         12-50                                                       Surface Active Agents                                                                           10-20                                                       Liquid Sodium Silicate                                                                          5-8                                                         Soil Redeposition Agents                                                                        0.5-1.5                                                     Fluorescent Dyes  0.05-1                                                      Water             2-12                                                        Sodium Sulfate    Balance                                                     ______________________________________                                    

Surface active agents mainly consist of anionic linear alkyl benzenesulfonate (LAS) and non-ionic alcohol based ethoxylates (AEO). Asurfactant is needed in the detergent to extend the functionalperformance of the detergent builder.

Non-ionic surfactants are added at a level of 4-6% (typical non-ionicsurfactants currently being used are Shell's Neodol 25-7 and 45-11)based on the weight of other ingredients of the detergent compositions.The resulting slurry is spray dried. Non-ionic surfactants contain smallfractions of short-chain molecules called "light ends." During the spraydrying step, the "light ends" do not incorporate into the finisheddetergent bead and go out of the dryer exhaust and result in a whitecloud referred to as "plume."

Detergent producers are anxious to cut down this "plume"and severalmechanical advances have been made to scrub the stack gases but thescrubbing process is not 100% effective. Also, the equipment required toclean the stack gases is very expensive.

We have found an inexpensive solution to the problem in which SAMS ofthe present invention can be used to convert the liquid non-ionicsurfactants to dry, free-flowing particulates so that dried-upsurfactant can be post added to the spray dried detergent formulation.Thus, SAMS compositions of the instant invention are useful fordrying-up non-ionic surfactants in the free-flowing form. Thus, SAMS canbe used in the detergent compositions to solve an air pollution problemcalled "pluming."

Neodol 25-9 surfactant (manufactured by Shell Chemical Company) wasdried-up on SAMS from Examples One and Two. The maximum amount of Neodolthat can be dried up is listed in Table XIV.

                  TABLE XIV                                                       ______________________________________                                        DRYING-UP NEODOL 25-9 ON SAMS PRODUCTS                                                          Flow Time % Active                                          Carrier           (seconds) Surfactant                                        ______________________________________                                        SAMS (Example One)                                                                              18        51.2                                              SAMS (Example Two)                                                                              15        55.9                                              Clay Control      86        10.0                                              ______________________________________                                    

From data in Table XIV above, it is clear that SAMS compositions ofExamples One and Two exhibit superior flow properties and dryingcapacity when compared with the corresponding control clay used inExample Two.

Thus, the method of drying up non-ionic surfactants results in superiorfree flowing surfactant powders. These surfactant powders can beefficiently used by post-adding to detergent compositions. Thus, SAMS ofthe instant invention are useful in detergent compositions and theseSAMS pigments impart superior properties which help in solving animportant air pollution problem.

12. PLASTIC FILM ANTIBLOCK COMPOSITIONS

Low density polyethylene (LDPE) and polypropylene (PP) film have atendency to stick together. This phenomenon is called "blocking." SAMSpigments of the instant invention were evaluated to determine if SAMScould be used as antiblocking agents in LDPE, PP and other plasticsfilms.

Approximately 1300 gram batches of LDPE and SAMS compositions fromExamples One and Two, as well as the control clay from Example Two, werecompounded in the 3# Banbury. Each sample was then granulated andextruded through the one and one-half inch Davis Standard Extruder usinga 20/100/60 mesh screen pack. Each sample extruded contained 90% LDPEGulf Resin 5200 and 10% of either the SAMS composition from Example Oneand Two, or the control clay from Example Two. Press-outs from eachconcentrate were made from each sample to determine the quality anddispersion of each material.

Film was then produced on the one-inch Killion extruder. All filmsamples were produced on the same machine on the same day at a constantrpm, identical temperature profile, and constant film thickness.

Film samples were heated after 24 hours of film aging to let theantiblock additive migrate to the surface of the film. The blockingforce, coefficient of friction (COF) and percent haze were determined oneach film sample. These results are summarized in Table XV.

                  TABLE XV                                                        ______________________________________                                        ANTIBLOCK COMPOSITION (FILM THICKNESS: 2 MILS)                                                       Blocking         %                                     Compound  Antiblock Agent                                                                            Force, gm COF, g Haze                                  ______________________________________                                        Gulf Resin 5200                                                                         None         76        0.6    11                                    Gulf Resin 5200                                                                         HG-90 Clay   74        0.5    12                                    Gulf Resin 5200                                                                         SAMS from    38        0.5    10                                              Example One                                                         Gulf Resin 5200                                                                         SAMS from    45        0.4    9                                               Example Two                                                         ______________________________________                                    

Data in Table XV clearly show that SAMS have better antiblockingproperties than the starting resin and the clay control. Also, the COFand the haze properties of the film containing SAMS are definitelysuperior to the film containing the clay control.

SYNTHESIS OF SAMS AS A FUNCTION OF B/C RATIO

Except as expressly noted below the procedures of Example One and Twowere followed using laboratory reactors of two-liter, one-gallon ortwo-gallon capacity in carrying out the examples below which areotherwise abbreviated to focus on the variables changed. Experimentationwas performed on a laboratory scale.

EXAMPLE THREE

A reaction in accordance with Example Two was carried out at 135 psi,for one hour of reaction time using Hydragloss 90 and a 2.5 mole ratiosodium silicate to illustrate the novelty of the invention over a widerange base to clay ratios. Conditions and results are shown below inTable XVI.

                  TABLE XVI                                                       ______________________________________                                        SAMS SYNTHESIS AS A FUNCTION OF B/C RATIO                                                             Monovalent                                            Base to       Oil       Cation Exchange                                       Clay Ratio    Absorption,                                                                             Capacity,                                             B/C           ml/100 g  meq/100 g                                             ______________________________________                                        Clay Control  30        2                                                     .20           89        72                                                    .35           127       123                                                   .50           164       170                                                   .70           124       189                                                   .90           122       186                                                   ______________________________________                                    

This clearly points to the fact that a wide variety of SAMS compositionsof high oil absorption and high ion exchange capacity, when comparedwith control clay, can be prepared by the teachings of the presentinvention.

EXAMPLE FOUR

To illustrate the present invention in regard to the use of differentalkali metal silicates, reactions of potassium silicates (Kasil 42 andKasil 1, respectively) with Hydragloss 90 clay were conducted at 120psig over 1.5 hours using 10% solids. Reactions conducted at B/C ratiosranging from 0.25 to 5.0 yielded the results set forth in Table XVII.

                                      TABLE IVII                                  __________________________________________________________________________    SAMS Synthesis from Potassium Silicate                                        Starting                                                                           B/C      Oil Absorption                                                                        BET S.A.,                                                                           Brightness                                        Silicate*                                                                          Ratio    ml/100 g                                                                              m.sup.2 /g                                                                          %     XRD                                         __________________________________________________________________________    --   HG-90 (control)                                                                        43      22.0  91.0  Kaolin                                      Kasil 42                                                                           0.26     146     27.1  90.0  attenuated Kaolin                           "    0.50     170     22.2  90.3  "                                           "    0.75     166     19.3  91.0  "                                           "    1.00     166     18.3  91.8  Amorphous                                   "    1.50     152     15.2  92.5  "                                           "    3.00     143     11.7  92.6  "                                           "    5.00     142     10.4  92.8  "                                           Kasil 1                                                                            0.25     159     29.9  90.2  Attenuated Kaolin                           "    0.50     167     26.6  90.9  "                                           "    0.75     170     21.9  91.9  Kaolin (trace)                              "    1.00     170     19.7  92.4  Amorphous                                   "    1.50     155     13.4  91.8  "                                           "    3.00     116     6.8   90.6  "                                           __________________________________________________________________________     *The SiO.sub.2 /K.sub.2 O mole ratio compositions of the starting             silicates were:                                                               Kasil 42 = 2.8                                                                Kasil 1 = 3.9                                                                 Silicates are commercially available from PQ Corporation.                

The data in Table XVII clearly shows that potassium silicates can alsobe used in the synthesis of unique SAMS compositions. A uniquecharacteristic of SAMS products prepared from potassium silicates is theabsence of zeolite formation even at B/C ratios as high as 5.0. At highB/C ratios (i.e., B/C>1), the potassium silicate/clay reactions werefound to always yield completely amorphous materials rather than anyzeolite. Under similar reaction conditions, sodium silicate/clayreactions typically produce zeolite (see Example Nine for comparison).Another interesting feature of potassium SAMS products, is an observedchange in their morphology as the SiO₂ /K₂ O mole ratio of the potassiumsilicate used for reaction is increased from 2.8 to 3.9. SEM photographscomparing the potassium SAMS prepared from Kasil 42 and Kasil 1, both atB/C ratio of 0.5, are shown in FIG. 39. A change in the agglomeratemorphology of the products, from generally spheroidal to coral-like, isapparent when Kasil 1 rather than Kasil 42 was used.

EXAMPLE FIVE

In accordance with the teachings of this invention, Example Five showsthe formation of SAMS compositions at B/C ratios of 1.0 to 2.0, usingalkali metal silicate bases of different SiO₂ /Na₂ O molar ratios. Toexemplify this aspect of the invention, a Hydragloss 90 clay was reactedwith 2.5 and 3.3 mole ratio sodium silicate at approximately 100 psi forone hour at 10% solids. The results are set forth in Table XVIII.

                  TABLE XVIII                                                     ______________________________________                                        SYNTHESIS OF SAMS AT HIGH B/C BATCH                                           COMPOSITIONS                                                                        Base to  Oil            Sur- Cation                                           Clay     Absorp-        face Exchange                                                                              Bright-                            Test  Ratio    tion,    Struc-                                                                              Area,                                                                              Capacity,                                                                             ness                               No.   (B/C)    ml/100 g ture  m/g  meg/100 g                                                                             %                                  ______________________________________                                        Hydra-                                                                              90                                                                      gloss Control  30       VLS   20   2-3     91.0                               1*    1        162      MS    24   141     91.7                               2*    2        193      HS    19   191     93.0                               3**   1        187      HS    16   159     92.6                               4**   2        115      LS    11   136     91.2                               ______________________________________                                         *2.5 Silicate Mole Ratio (SiO.sub.2 /Na.sub.2 O)                              **3.3 Silicate Mole Ratio (SiO.sub.2 /Na.sub.2 O)                        

Data in Table XVIII clearly show the formation of SAMS compositions atB/C ratios equal to and greater than 1.0 using alkali metal silicatebases of different SiO₂ /Na₂ O molar ratios. The SAMS compositions hadoil absorption values which would correspond to materials having fromlow (LS) to high (HS) structure. TEM FIGS. 22 and 23 also show the sameunique SAMS composition and morphology of SAMS compositions prepared atB/C ratios of 0.5 and 0.75 (FIGS. 18 through 21).

FIG. 5 shows a comparison of the FT-IR spectra of Hydragloss 90 controlclay, SAMS from Example Two prepared at a B/C of 0.5, and SAMS fromExample Five prepared at a B/C of 1.0 and 2.0. A sodium silicate havingan SiO₂ /Na₂ O mole ratio of 2.5 was used in the SAMS synthesis. Theonly difference observed in the IR spectra of the SAMS compositionsoccurred in the 1200-950 wavenumber region in the Si-O stretching peak.As the B/C of the SAMS composition increased the peak became broader andless detailed. This would indicate an increase in the amount ofamorphous material present in the SAMS compositions. The TEMS's andFT-IR spectra clearly show that the unique SAMS compositions can beformed at B/C ratios of one and greater.

To further demonstrate the functionality feature of the variety of SAMScompositions prepared at different B/C ratios, the products from Tests 1through 4 were evaluated as functional extenders in a typical paintformulation similar to that described earlier. In Table XIX the productsfrom Tests 1 through 4 were compared in contrast ratio with Zeolex 80,Hydragloss 90 and Satintone 5, a commercial, high brightness calcinedclay.

                  TABLE XIX                                                       ______________________________________                                        PAINT PROPERTIES OF SAMS VERSUS B/C                                           OF BATCH COMPOSITION                                                                            Silicate           Contrast                                 Test No.   B/C    Mole Ratio  Structure                                                                            Ratio                                    ______________________________________                                        1          1      2.5         MS     .977                                     2          2      2.5         HS     .978                                     3          1      3.3         HS     .975                                     4          2      3.3         LS     .970                                     Satintone 5       --          VLS    .975                                     Hydragloss 90     --          VLS    .976                                     Zeolex 80         --          LS     .973                                     ______________________________________                                    

As noted in Table XIX, the SAMS compositions having medium to highstructure produced excellent contrast ratio values which equalled orsurpassed values for commercially available calcined clays or silicas inpaint properties.

EXAMPLE SIX

To illustrate the present invention in regard to the use of silicatescomprised of various SiO₂ /Na₂ O ratios, a reaction of Omnifil andvarious silicates at a pressure of 120 psi for one hour of reaction timeat 10% solids yields the results set forth in Table XX.

                                      TABLE XX                                    __________________________________________________________________________    SYNTHESIS OF SAMS AS A FUNCTION OF SILICATE MOLE RATIO                                   Silicate  Monovalent                                                          Mole      Cation                                                        Base to                                                                             Ratio                                                                             Oil   Exchange                                                                             Surface                                                                            Bright-                                      Test Clay Ratio                                                                          (SiO.sub.2 /                                                                      Absorption,                                                                         Capacity,                                                                            Area,                                                                              ness,                                                                             Struc-                                   No.  (B/C) Na.sub.2 O)                                                                       ml/100 g                                                                            meq/100 g                                                                            m.sup.2 /g                                                                         %   ture                                     __________________________________________________________________________    1    .50   3.33                                                                              161   115    24   83.5                                                                              MS                                       2    .75   3.33                                                                              167   149    20   85.8                                                                              MS                                       3    .50   2.50                                                                              156   143    25   85.5                                                                              MS                                       4    .75   2.50                                                                              148   175    21   85.9                                                                              MS                                       5    .50   1.00                                                                              123   148    28   84.0                                                                              LS                                       6*   .75   1.00                                                                              83    216    28   85.1                                                                              LS                                       Omnifil (Control)                                                                        --  37    2-3    20   82.0                                                                              VLS                                      __________________________________________________________________________     *XRD pattern showed presence of zeolitic material                        

As can be seen from the data in Table XX, SAMS compositions having lowto medium structure were formed under the preferred conditions of B/Cless than 1.0 using alkali metal silicate bases of varying SiO₂ /Na₂ Omolar ratios. Low structured SAMS compositions prepared in Tests No. 5and 6 using sodium metasilicate. The XRD pattern of Test 6 showed thepresence of a zeolitic material. FIG. 6 shows a comparison of theinfrared spectra of the SAMS compositions of Example Six prepared at aB/C ratio of 0.5 using the different molar ratio sodium silicates. TheIR spectra of the SAMS prepared from the 2.5 and 3.3 mole ratio silicateare essentially identical and closely resemble the IR pattern of theSAMS compositions of Example One, Two and Five (FIGS. 3, 4 and 5). TheIR spectrum of the SAMS prepared with meta silicate more closelyresembles that of the starting clay (FIG. 3), reflecting the lowersilicate content of the starting reaction mixture. This is especiallytrue in the 1200-950 wavenumber Si-O stretching region. It must beconcluded, based on the physical and analytical data, that unique SAMScompositions similar to those produced in Example One and Two wereformed by reacting clay with sodium silicates of SiO₂ /Na₂ O molarratios of 1.0 to 3.3 at B/C ratios less than 1.0.

EXAMPLE SEVEN

To illustrate the effectiveness of the present invention on a claypigment produced from another locale, a delaminated Central Georgia clay(Hydraprint) having the properties shown in Table XXI was employed for athree-hour reaction time at 120 psi and 10% solids, using a 3.33 moleratio sodium silicate. Results of the reactions are shown in Table XXI.

                  TABLE XXI                                                       ______________________________________                                        SYNTHESIS OF SAMS FROM CENTRAL GEORGIA CLAY                                   Base to   Oil          Surface                                                Clay Ratio                                                                              Absorption   Area,                                                  (B/C)     ml/100 g     m.sup.2 /g                                                                             Structure                                     ______________________________________                                        Hydraprint                                                                    (Control) 49           13       VLS                                           0.25      153          19       MS                                            0.50      179          14       HS                                            0.75      171          14       MS                                            ______________________________________                                    

The oil absorption data shown in Table XXI would suggest that uniqueSAMS compositions of medium to high structure can be produced by thereaction of a relatively coarse particle size, low surface area claysuch as Hydraprint with an alkali metal silicate base.

EXAMPLE EIGHT

To illustrate the importance of controlling reaction time andpressure/temperature in the SAMS synthesis, a series of SAMS reactionswas conducted in which pressure and reaction time were varied between100-150 psi and one to three hours, respectively. Results of the testsare shown in Table XXII. The reactions were conducted at 10% solidsusing a Hydraprint, middle Georgia delaminated clay, and a B/C ratio of0.8. A 3.3 mole ratio sodium silicate was used in the tests.

                  TABLE XXII                                                      ______________________________________                                        SYNTHESIS OF SAMS AS A FUNCTION OF REACTION,                                  PRESSURE AND TIME                                                                             Bright- Oil                                                   Pressure,*                                                                            Time,   ness,   Absorption       SA,                                  psi     hrs.    %       ml/100 g                                                                              XRD      m.sup.2 /g                           ______________________________________                                        100     1       89.2    134     SAMS     13                                           2       90.0    135     SAMS     11                                           3       90.3    145     SAMS     11                                   120     1       89.9    131     SAMS     11                                           2       90.6    133     SAMS     11                                           3       91.1    157     SAMS +   112                                                                  Trace Z**                                     135     1       90.3    137     SAMS     9                                            2       91.2    156     SAMS +   33                                                                   Trace Z                                               3       91.3    161     SAMS + Z 91                                   150     1       90.6    144     SAMS     10                                           2       91.5    158     SAMS +   49                                                                   Trace Z                                               3       91.5    150     SAMS + Z 124                                  Hydraprint      87.5    42               14                                   (Control)                                                                     ______________________________________                                         *Corresponding temperatures can be found in steam table                       **Zeolite                                                                

The above tests illustrate the wide variety of SAMS compositions thatcan be produced by reacting clay and alkali metal silicate. Brightness,oil absorption and surface area of the resulting SAMS compositions canbe changed by varying reaction time and steam pressure (temperature).The data show that if the presence of zeolitic material in the SAMScomposition is undesirable, it can be eliminated by reducing reactionpressure and/or time.

EXAMPLE NINE

To illustrate the uniqueness of the clay-sodium silicate reaction, testswere conducted in which Hydragloss 90 east Georgia clay was reacted withboth a 2.5 molar sodium silicate and sodium hydroxide at B/C ratios of0.75 to 5.0. The reactions were conducted at 10% solids at 120 psi fortwo hours. Results of the tests are given in Table XXIII.

                                      TABLE XXIII                                 __________________________________________________________________________    COMPARISON OF SODIUM SILICATE WITH SODIUM HYDROXIDE                           AS BASE IN THE SAMS SYNTHESIS                                                 Base to Clay                                                                  Ratio,     Brightness,                                                                         OA,  SA,                                                     (B/C)  Base                                                                              %     ml/100 g                                                                           m.sup.2 /g                                                                       XRD                                                  __________________________________________________________________________    0.75   Silicate                                                                          92.1  147  90 SAMS                                                 1      Silicate                                                                          90.9  102  228                                                                              SAMS + trace Zeolite                                 3      Silicate                                                                          92.0  90   246                                                                              Trace SAMS + Zeolite                                 5      Silicate                                                                          93.5  104  7  Amorphous                                            0.75   NaOH                                                                              81.0  82   20 Hydroxy sodalite*                                    1      NaOH                                                                              74.6  78   15 Hydroxy sodalite*                                    3      NaOH                                                                              83.5  64   17 Hydroxy sodalite                                     5      NaOH                                                                              81.5  60   21 Hydroxy sodalite                                     Hydragloss                                                                           90  91.0  43   22.0                                                    __________________________________________________________________________     *XRD also showed presence of kaolinite.                                  

The reaction with sodium hydroxide formed only hydroxy sodalite. Inaddition, the low brightness, oil absorption and surface area valuesalso show that no SAMS compositions were formed. In contrast, the sodiumsilicate reaction produced SAMS compositions having increasedbrightness, structure (oil absorption) and surface area. The XRDanalysis of the silicate reaction products showed the presence ofzeolites at B/C ratios of 1.0 and higher. The amorphous character andlow surface area of the B/C=5 silicate reaction indicated the formationof a new phase.

FIG. 7 compares the spectra of the silicate reaction products in TableXXIII. The spectra show the presence of SAMS but also show the increasein zeolite formation at the higher B/C ratios as the Si-O stretchingpeak (1200-950 wavenumber) becomes sharper and the peaks typical ofkaolin located between 800 and 400 wavenumbers disappear.

FIG. 8, likewise, compares the IR spectra of the sodium hydroxidereaction products. The Si-O stretching peak (1200-950 wavenumbers) issharper, indicating the formation of a crystalline phase (hydroxysodalite), and the loss of peaks in the 800-400 wavenumber region isobserved at lower B/C ratios than for the silicate reaction.

EXAMPLE TEN Nylon Plastic Compositions Containing SAMS

Fillers are added to plastics to provide reinforcement or to act as aninexpensive diluent without resulting loss of physical properties. TheSAMS product of Example 2 was evaluated as a reinforcing filler inamorphous Nylon 66 at loadings of 5, 10 and 20% respectively. Thephysical properties of these filled compositions were then compared tothose of an unfilled Nylon plastic to assess the reinforcing potentialof SAMS.

Evaluation results for SAMS as a filler in amorphous nylon are tabulizedbelow:

                                      TABLE XXIV                                  __________________________________________________________________________    Nylon Reinforcing Properties of SAMS                                                                 SAMS from                                                            Nylon Control                                                                          Example 2 @                                                          (unfilled)                                                                             5%    10%   20%                                        __________________________________________________________________________    Tensile Modulus, psi                                                                        33880    54080 56850 103600                                     Tensile Yield, psi                                                                          4405     5057  5035  4214                                       Elong. @ Peak, %                                                                            371      324   297   114                                        Flexural Modulus, psi                                                                       47160    54670 64020 88590                                      Flexural Strength, psi                                                                      1933     2226  2491  3191                                       Izod Impact, ft-lbs/in                                                                      11.47 NB 14.12 NB                                                                            13.59 NB                                                                            13.40 NB                                   Gardner Drop Wt., in/lbs                                                                    >160     >160  >160  >160                                       __________________________________________________________________________

It should be noted that the filled compositions show marked advantagesin their tensile and flexural modulus values versus the unfilledcontrol. Impact properties were also excellent even at a 20% loading ofSAMS. However, advantages in the above physical properties were notobtained at the expense of any tensile yield or flexural strength. It isremarkable that the conversion of an inexpensive clay into a SAMSresults in such a unique functional filler for nylon.

EXAMPLE ELEVEN Conduit Pipe Composition Containing Sams

To further illustrate the plastic reinforcement properties of SAMS, theSAMS of Example One was evaluated as a filler in a conduit pipecomposition which utilizes a high-density polyethylene base resin(Phillips C-568). In this particular application, the SAMS of ExampleOne was surface modified with a standard, commercial-grade azido silanecoupling agent (Hercules AZ-CUP MC) at a 0.75% treatment level. Themodified SAMS was then incorporated into the HDPE resin at a 25% loadinglevel. The silane was added as in known clay technology by adding theazido silane in its pure form in up to 10% liquid involving dilution ofthe silane with methylene chloride or methanol followed by low shearsolid-liquid mixing with the SAMS using a device such as a Sigma BladeMixer. The physical properties of the SAMS/HDPE composite were thencompared to those of an unfilled HDPE control. Intergral Corporation's(of Dallas, Texas) criteria for their conduit compounds include goodprocessiblity, high tensile and stiffness properties and a minimum IzodImpact of 2.7 ft-lbs/in. Test results 15/8 inch O.D. pipe produced fromeach composition are tabulized below.

                  TABLE XXV                                                       ______________________________________                                        Reinforcing Properties of Modified SAMS*                                      in a Conduit Pipe Composition                                                                       HDPE with                                                           HDPE Control                                                                            SAMS/AZ-CUP                                                         (Phillips C-568)                                                                        At 25% Loading                                          ______________________________________                                        Tensile Modulus, psi                                                                        157800      223500                                              Tensile Yield, psi                                                                          5407        5269                                                Elong. @ Peak, %                                                                            11.57       12.41                                               Flexural Modulus, psi                                                                       105600      224100                                              Flexural Strength, psi                                                                      3393        5015                                                Izod Impact, ft-lbs/in                                                                      13.66       15.72                                               ______________________________________                                         *SAMS of Example One surface modified with Hercules azido silane (AZ  CUP     MC) at 0.75% treatment level.                                            

The test data clearly show that the SAMS/HDPE composition satisfies allthe physical property criteria needed by Intergral Corporation theirconduit applications. Versus the unfilled HDPE control, one will notethat modified SAMS addition provides notable improvements in the tensileand flexural modulus, flexural strength and izod impact properties. Itis therefore obvious that SAMS serves as a highly functional filler inthis plastic system.

EXAMPLE TWELVE

In accordance with the teachings of this invention, SAMS products wereevaluated as reinforcing fillers for high-density polyethylene at a 25%loading. The SAMS products for this filler application were preparedfrom a coarse particle size, Middle Georgia delaminated clay (i.e.,Hydraprint) in combination with a 3.3 mole ratio sodium silicate used atB/C ratios of 0.25, 0.50 and 0.75 respectively in accordance with theprocedure of Example 8. SAMS products were produced from the above batchcompositions by reaction at 120 psig for one hour at 10% solids. Theagglomerate products were in the form of platelets. The reinforcementproperties of these platey SAMS in HDPE were compared to those ofhydrous clays. The results are set forth in the table below.

                                      TABLE XXVI                                  __________________________________________________________________________    Reinforcing Properties of SAMS in Allied HDPE 7-731, 25% Loadings                                Filled HDPE Compositions at 25% Filler Loadings                          HDPE HP-  "Platelet" SAMS Products"                                           Control                                                                            Clay 0.25 B/C                                                                            0.50 B/C                                                                            0.75 B/C                                  __________________________________________________________________________    Tensile Modulus, psi                                                                        165500                                                                             312500                                                                             314400                                                                              295400                                                                              289700                                    Tensile @ Yield, psi                                                                        4359 4748 4762  4921  4969                                      Elong. @ Peak, %                                                                            11.2 7.6  6.8   7.6   8.1                                       Flexural-Modulus, psi                                                                       144000                                                                             303800                                                                             303500                                                                              289700                                                                              279300                                    Flexural-Strength, psi                                                                      4097 5929 6048  6014  5890                                      Izod Impact, ft-lbs/in                                                                      15.5 5.9  7.2   8.5   12.1                                      Gardner Drop Wt., in/lbs                                                                    >160 131  >160  >160  >160                                      __________________________________________________________________________

The test data clearly indicates that platey SAMS products, when used asfillers for HDPE, provide physical properties essentially equivalent tothose provided by hydrous clays, except with respect to Izod Impactwhich was improved. The platey SAMS provided notable advantages in IzodImpact, particularly as their B/C ratio increased from 0.25 to 0.75. Itis truly unexpected that the conversion of a delaminated clay into aplatey SAMS product of high B/C should produce a unique functionalfiller for HDPE. An increase in impact strength from approximately 5 upto 12 ft-lbs/in is considered very significant.

EXAMPLE THIRTEEN

Platey SAMS products of B/C ratios of 0.25, 0.50 and 0.75, respectively,prepared as in Example Twelve, were evaluated as coating pigments forpaper that was used in a printing application by the rotogravure method.All pigment coatings were applied to the paper substrate at a coatweight of 5.0#/R using a Keegan laboratory blade coater. Followingsupercalendering, coated sheets were tested for sheet smoothness and forvarious optical properties (including brightness, opacity and printedgloss) in accordance with standard TAPPI test methods. Test coatingcompositions containing platey SAMS were prepared by simply replacing 5%of the standard, commercial-grade of delaminated clay (Hydraprint) withthe desired SAMS product. Coating compositions containing 100%Hydraprint, 90% Hydraprint/10% calcined clay (Hycal) for their pigmentportions were also prepared and evaluated as comparative controls. Therotogravure printing results are tabulized below.

                                      TABLE XXVII                                 __________________________________________________________________________    Sheet Properties for SAMS Paper Coating Compositions* (Rotogravure            Printing)                                                                                     90% HP-Clay                                                                            95% HP-Clay + 5% Platey SAMS Product                            100% +10% Calcined                                                                          SAMS of                                                                              SAMS of                                                                              SAMS of                                           HP-Clay                                                                            Clay     0.25 B/C                                                                             0.50 B/C                                                                             0.75 B/C                               __________________________________________________________________________    Brightness, %                                                                            70.0 72.6     71.1   70.7   70.6                                   Opacity, % 85.2 86.8     86.1   85.7   85.9                                   Printed Gloss, %                                                                         60.8 56.1     59.9   56.7   57.1                                   Missing Dots/Sheet**                                                                     48   40       27     28     24                                     __________________________________________________________________________     *Coating Parameters were as follows:                                          Base Stock = 24 #/R St. Regis Offset (wire side)                              Application = Keegan Trailing Blade Coater                                    Coat Weight = 5.0 #/R                                                         Calender Conditions = Supercalendered using 800 PLI                           at 150° F. and 2 Nips                                                  **Diamond National Smoothness Test                                       

The observed sheet properties indicate that the replacement of only 5%delaminated clay with platey SAMS results in several notable performanceimprovements. Versus a straight delaminated clay composition, 5% of aplatey SAMS significantly improved brightness, opacity and sheetsmoothness. Although platey SAMS at 5% replacement did not provide quitethe level of sheet brightness and opacity provided by the 10% calcinedclay, the printed gloss and sheet smoothness properties provided byplatey SAMS were far superior. Consequently, in those printingapplications where printed gloss and sheet smoothness are of utmostimportance, platey SAMS will out perform calcined clay used at doublethe concentration level. The above test data also clearly indicate thatplatey SAMS products of low B/C ratio (i.e., about 0.25) are preferredcoating pigments on the basis of their overall performance properties.

The platey morphology of the sodium SAMS products prepared fromdelaminated clay (i.e., Hydraprint) is clearly seen in their SEMphotographs presented in FIGS. 40-41. A comparative SEM photograph ofthe starting Hydraprint clay is shown in FIG. 42. The above photographssuggest that SAMS prepared from Hydraprint largely maintain the flat,platey structure inherent in the delaminated clay. The unique physicalproperties exhibited by such platey SAMS are therefore a consequence ofthe observed rim alteration material. The degree of rim alteration(i.e., the rim width) can be easily varied on platey SAMS depending onthe specific synthesis conditions employed. Comparison of the plateySAMS prepared at B/C ratios of 0.25 and 0.75 (FIG. 40 versus FIG. 41)shows that increased rim alteration occurs at the higher B/C ratio. Thephysical properties of these two SAMS therefore differ significantly, asshown below:

                  TABLE XXVIII                                                    ______________________________________                                        Comparison of Properties for Two Platey SAMS of Different B/C                                  Platey SAMS Product*                                                          SAMS of                                                                              SAMS of                                                                0.25 B/C                                                                             0.75 B/C                                              ______________________________________                                        Brightness, %      89.7     90.9                                              Oil Absorption, ml/100 g                                                                         97       117                                               BET Surface Area, m.sup.2 g                                                                      15.7     9.3                                               Na.sub.2 O Content, %                                                                            3.75     6.93                                              LOI (@ 1000° C.), %                                                                       11.45    8.97                                              Kaolin Content (XRD), %                                                                          55.2     18.1                                              Rim Alteration     thin     thick                                             ______________________________________                                         *Platey SAMS prepared in accordance with reactions described in Example       Twelve.                                                                  

Platey SAMS are not as structured as agglomerates of SAMS of ExamplesOne and Two. The apparent reluctance of large, delaminated clayplatelets to agglomerate upon hydrothermal alteration further lendsitself to platey SAMS formation. Given the flat, platey structure ofSAMS prepared from Hydraprint, it is not surprising that these productsimpart excellent sheet smoothness and printed gloss when used as papercoating pigments.

EXAMPLE FOURTEEN

This example further illustrates the present invention with regard tothe use of lithium silicates as an appropriate alkali metal silicatebase for producing SAMS products. Reactions between a lithium silicate(Lithsil 4) and Hydragloss 90 clay were thereby conducted at 120 psigfor 1.5 hours at 10% reaction solids using B/C ratios of 0.25, 0.50 and0.75 respectively. Results from these lithium silicate/clay reactionsare set forth in the table below.

                                      TABLE XXVIV                                 __________________________________________________________________________    SAMS Synthesis from Lithium Silicate                                          Selected      Hydragloss 90                                                                          Li - SAMS Products                                     Properties    (Clay Control)                                                                         0.25 B/C                                                                            0.50 B/C                                                                            0.75 B/C                                   __________________________________________________________________________    Oil Absortion, ml/100 g                                                                     43       81    92    97                                         BET Surface Area, m.sup.2 g                                                                 22       28    22    25                                         Brightness, % 91.0     88.9  90.1  91.2                                       Specific Gravity g/ml                                                                       2.60     2.53  2.50  2.45                                       LOI (@ 1000° C.), %                                                                  13.86    12.17 11.61 11.11                                      Li.sub.2 O Content, %                                                                       0.0      0.89  1.26  1.47                                       __________________________________________________________________________     *The lithium silicate employed had a 4.8 SiO.sub.2 /Li.sub.2 O mole ratio     composition (Lithsil 4 of Lithium Corporation)                           

The above data clearly shows that a lithium silicate can be used in thesynthesis of unique SAMS compositions.

Examination of the lithium SAMS compositions by TEM and STEM/EDAXmethods revealed that an alteration product was indeed produced as aconsequence of the lithium silicate/clay reaction. The TEM photograph ofthe 0.75 B/C product (FIG. 43) clearly shows the presence of some dark,blobby masses or protuberances on the kaolinite platelets. Electrondiffraction analysis indicates that these protuberances or blobby massesare totally amorphous, while the remaining platelet areas show thetypical diffraction pattern for the remaining platelet show the typicaldiffraction pattern for kaolinite. Most importantly, one should notethat the blobby masses or protuberances did not form exclusively on theclay platelet edges, but appear in a more or less random fashion aboutthe platelets. Several pseudo-hexagonal clay platelets are still clearlyevident in the TEM photograph which indicates great heterogeneity ofreaction. Elemental mapping of the Si and Al content within a lithiumSAMS material, by STEM/EDAX analysis, has indicated that the alterationproduct (i.e., the blobby masses) is much higher in silicon anddeficient in aluminum relative to the unaltered kaolinite regions.Elemental mapping of lithium was not possible because its atomic weightis below the detection limit of the instrument.

SUMMARY

As suggested by the above examples, the materials of the presentinvention may be used as effective pigment (titanium dioxide) extendersin paint and paper applications, as functional fillers or reinforcingagents in plastics and elastomers, as a catalyst support and carrier incatalyst preparation, as a thixotrope, as a conditioning and free flowagent, and in defoamer compositions. Because of their low abrasioncharacteristics, the materials of the present invention may be used tofill Xerox and electrostatic copier papers. Products of the presentinvention can also be used in a variety of specialty applications and asa n opacifier, a diazo paper filler, a flatting agent, in siliconerubbers and other applications.

In addition, the SAMS compositions, because of their unique physical andchemical properties, may be used in certain catalytic applications ifthey are first exchanged with hydrogen, ammonium or other suitablecation, i.e., either as a separate particle or intimately mixed with thecomponents of a hydrocarbon conversion catalyst. Moreover, the widevariation one can achieve in surface area, pore volume, SiO₂ /Al₂ O₃ratio, and ion exchange capacity (solution or gas phase) suggest theirapplication for emission control catalysts and in metal scavenging, andin the clean-up of residue materials and/or resid-type feeds to fluidcatalytic cracking units in particular.

In the preferred embodiment of the invention, x is an integer of 0.01 to2.0, y is an integer of at least 2.0 and preferably 2.0 to 20.0 and z isan integer of 1.0 to 5.0.

The terms Hydraprint, Hydragloss, Huber 90C, Omnifil, Hydrasperse,Hycal, Zeolex 23, Hydrex, Zeolex, Zeolex 23P, Zeo, Zeosyl, Zeofree andZeodent used herein are trademarks of the J. M. Huber Corporation.Hi-Sil is a registered trademark of PPG and Ansilex is a registeredtrademark of Engelhard Corporation.

Although a specific preferred embodiment of the present invention hasbeen described in the detailed description above, the description is notintended to limit the invention to the particular forms or embodimentsdisclosed herein. The present disclosure is to be recognized asillustrative rather than restrictive. It will further be obvious tothose skilled in the art that the invention is not so limited. Theinvention is declared to cover all changes and modifications of thespecific examples of the invention herein disclosed for purposes ofillustration, which do not constitute departures from the spirit andscope of the invention.

What is claimed is:
 1. A paper containing a paper coating comprising analkali metal alumino-silicate having a composition in terms of moleratio of oxides as follows:

    xM.sub.2 O:Al.sub.2 O.sub.3 :ySiO.sub.2 :zH.sub.2 O

wherein x is the number of moles of alkali metal oxide and is an integerof 0.01 to 2.0, M is an alkali metal, y is the number of moles of SiO₂associated with the compositions and is an integer of 2.0 to 20.0, and zis the number of moles of bound water and is an integer of 1.0 to 5.0,wherein primary particles of said alkali metal alumino-silicate comprisea core of clay platelets having an integral adjacent area of essentiallyamorphous alkali metal silicate base-kaolin clay reaction product.
 2. Apaper composition according to claim 1 wherein the alkali metalaluminosilicate has the morphology of the integral rimmed particles asdepicted in TEM FIGS. 18-23.
 3. A paper containing a coating whichcomprises an alkali metal alumino-silicate comprising a core of kaolinclay platelets which have been altered at their edges by reaction so asto be integral with one or more adjacent areas of essentially amorphousalkali metal silicate-base kaolin clay reaction product having acomposition in terms of mole ratio of oxides as follows:

    xM.sub.2 O:Al.sub.2 O.sub.3 :ySiO.sub.2 :zH.sub.2 O

where M is sodium or potassium, x is the number of moles of sodium oxideor potassium oxide and is an integer of 0.01 to 2.0, y is the number ofmoles of SiO₂ in the composition and is an integer greater than 2.0, andz is the number of moles of bound water and is an integer of 1.0 to 5.0;wherein the primary particles of said alkali metal alumino-silicate haveattenuated kaolin peaks as compared to kaolin in x-ray diffractionpatterns from the kaolin remnants in the compositions, and have the IRscan shown in FIGS. 3-6.
 4. A paper according to claim 3 wherein thealkali metal silicate is sodium silicate, and the silicate product has arimmed structure comprising silica.
 5. A paper according to claim 3wherein the alkali metal silicate is potassium silicate and the silicateproduct has a rimmed structure comprising silica and potassium.
 6. Apaper according to claim 3 wherein the alkali metal silicate is lithiumsilicate and the silicate product comprises a platelet area withamorphous protuberances thereon.
 7. A paper according to claim 3 whereinthe silicate composition also contains at least a trace of a zeolitecomposition.
 8. A paper according to claim 3 wherein the silicatecomposition has an oil absorption value having a range between about 40to 220 ml/100 g, and a surface area of about 2 to 300 m² /g.
 9. A paperaccording to claim 3 wherein the silicate compositions have an oilabsorption range of between 80 to 160 ml/100 g and a surface area rangebetween 10 to 30 m² /g.